I have tried several 4-port HDMI KVM switches from Amazon that are about half the price of this one. Although they were usable, and one I have been using for about 6 months, I was not happy with the build quality, especially the switching buttons.So I kept looking, and decided to try this one. It is by far more expensive than the budget models, but I feel it is worth it and this will become my new HDMI KVM. This review is for the 4-port HDMI USB 3.0 version.BUILD QUALITY:Firstly, this is a solid device with excellent build quality. No cheap feeling that some of the others I have tried have had. The connectors for the cables are all solid and the 4 buttons for device selection are easy to press and make contact the first time.FEATURES:This KVM has more features than the others. Firstly, it has a USB 3.0 switcher, rather than USB 2.0 as most have. It has multiple configurable ways to switch devices (buttons on the front, wired remote controller, mouse or keyboard shortcuts which can be changed). You can also enable/disable the beep upon device switching. You can also turn on and off the keyboard shortcut recognition through a dedicated button on the front of the device. Some of the other models require a key sequence to accomplish this. There is also an audio output on the front which mirrors the audio coming through the HDMI port. There is apparently an auto-scan feature but I did not try that feature.AUDIO:I thought the audio output would appear on each computer as a new sound device via USB, but it isn't. It takes the audio being sent to the HDMI output and routes it to this jack. The manual says to set each computer's default audio device to the HDMI output, and then plug your speakers into the jack on the KVM. (Note, the audio is still routed to your monitor over HDMI so you don't lose that, even if you're not using the audio output on the front). This is neat, but it seems to me that the audio out jack is not very high quality, it seems to be missing some of the high frequency content. If your monitor has a headphone jack you could accomplish the same thing by utilizing that. The audio that is output through the audio jack is only the audio of the selected system. A nice additional feature might be to have the option of mixing the audio from all four systems together, no matter if they are selected or not, so that you wouldn't lose audio from non-selected systems.REMOTE:This particular model has a wired remote control. The manual says that if you plug it in, the front panel buttons are disabled. However, I found that to be false. I can use either the remote or the front panel buttons. The remote has lights on it to show you which device is selected. This is a nice feature if you've got the KVM mounted on the back of a workbench, you can bring the controls out to the front of the bench,MONITOR HANDLING:The cheaper KVM switches that I tried would completely disconnect the monitor from the systems not in use. This meant that when you switch from one system to another, the system you were switching away from would "lose" the HDMI monitor and the system you were switching to would "add" it. This switch works differently - all systems always see your monitor as being connected, and the switch just throws away the video from the systems that are not the selected device. I find this to be much more reliable as your systems are not constantly losing and adding a monitor. It also makes for faster switching.KEYBOARD/MOUSE:This switch is supposed to be compatible with wireless keyboards and mice, and I see no reason why it would not be. However, there can be an issue with some keyboards that are not just plain keyboards. For example, my HyperX Alloy Elite does not always work as expected. I have my mouse (wireless) receiver connected into the back of the keyboard, and the keyboard has two cables - one for the keyboard and one for the USB port on the back of the keyboard that my mouse receiver is in. I have these two cables plugged into the KVM in the appropriate connection jacks. Although sometimes switching does work correctly, I have also had instances where the mouse will not be recognized on the system I'm switching to without unplugging the USB cable for the mouse and plugging it back in. The manual does state that some gaming keyboards may have issues and to disable the keyboard shortcut switching. The manual says to use keyboard shortcuts to do this, but since this model also has the front switch for this purpose, I tried that. Once keyboard shortcuts were disabled, I have not had an issue switching between systems with recognition of my keyboard or mouse. I do however lose the capability of using keyboard shortcuts to switch systems, which I don't need anyway. I do plan to try and plug the wireless mouse receiver directly into the KVM but because the keyboard and mouse USB jacks are so close together, I will need a USB extension cable to accomplish this.PERFORMANCE:This KVM performs quite well. Switching between systems is fast. However, because of the way Windows 7 handles USB (slowly) when switching to a Windows 7 system it could possibly take a little more time for your keyboard and/or mouse to be re-recognized. This may not be true on all Windows 7 systems however, but it is what I have experienced. My Windows 10 systems switch quickly and flawlessly. I find having the HDMI monitor not disappear when switching away is a huge plus for this KVM.PACKAGE:This is a complete package. You get 4 HDMI cables, 4 USB 3.0 A to B cables, a power adapter (which seems to not be necessary as the switch can get its power from the connected system(s)), and wired remote + cable. You just need to supply your own HDMI to connect to the output monitor and your own keyboard and mouse connection cable(s) or dongles. Not as I mentioned above the jacks for keyboard and mouse are close together and I was not able to fit a USB cable and a direct connected Logitech unified receiver without using a USB extender cable.PROS: * Excellent build quality * Button, wired remote, or configurable key/mouse shortcut switching modes * All cables included * Can turn switching beep on/off * Auto scan mode * Wired remote with lights works in addition to front panel buttons * Rubber feet on bottom of device * Front button to turn off keyboard switching shortcuts * Audio output jack replicates HDMI audio * Fast switching * No loss of HDMI monitor identification when system is not in use * Supports USB 3.0 devices to switch to selected device * Compact size, and unit has good weightCONS: * Can be finicky to work with gaming keyboards, but can disable shortcuts as a workaround * No mounting holds on bottom of device. Could use Velcro to mount/secure it * Device is small, so lots of cables all connected to one small unit * No lights to show USB or HDMI status of conencted systems(s). Only lights to show selected systemCONCLUSION:I did not initially buy this model because of the price, and thought some of the other units that were half the price would be as good or workable. However, now I wish I had just "bitten but bullet" and bought this one to start with. So, if you want a 4 port HDMI KVM with USB 3.0 (even if you really don't need USB 3.0) just get this one.After a great amount of research I decided to get this. The reviews I read were mostly positive, and I add mine to that.One thing that I had a hard time with was deciding if the USB 3.0 version from this manufacturer was worth the considerable extra expense. They have a much cheaper USB 2.0 version, but I got the 3.0 and I'm so glad I did. The reason being I have a gaming mouse that wasn't recognized when I plugged it into the dedicated keyboard/mouse port. I plugged it into the 3.0 port and it worked like it should. I didn't know this would be an issue and I'm happy to know, should I have another accessory that has this requirement, it will work appropriately.The only real complaints I have are the placement of the accessory ports on the front and the lack of 3.5mm mic support.I don't have a lot of desk space and the cords that plug in take up some of that prime real estate. I had to buy some right angle extensions so they would go to the side, but I would have preferred to be able to just plug them into the side. A minor complaint, but enough of one to mention. I also would have appreciated a speaker/mic audio port over just the speaker, but that's easy enough to work around with a USB adapter (which coincidentally I have plugged into the keyboard/mouse port I moved the mouse from).I can't really add any more than that. I love this thing. I have it connected to my work computer, home computer, Xbox and home media server, making the transition to each smooth as buttah! Stop your search and just get this thing. You won't regret it.I've made this work for my needs and have no complaints right now. A couple things:1. The dedicated keyboard and mouse usb ports don't work with my wireless keyboard and mouse (Logitech K800 and Razer Deathadder Pro v2). The usb ports to the left of the dedicated ports work fine.2. The unit started making an uncomfortable loud whirring sound which I assumed is some kind of fan but upon inspection is some fast-spinning gear which is actually visible from the back side. I opened up the unit and unplugged this gear/fan/whatever from the control board and it is now silent. Unplugging this doesn't seem to have any detrimental effects so far (a couple months later).I have to assume that this loud spinning thing is in there for a good reason, but I'm rolling the dice on this alteration as the sound is too distracting.I use this device with a Windows machine. So far, out of four different KVM switches I have tried, this is the best (TrippLite, goFanco Prophecy and another brand I don't remember). The greatest advantage of this one is a good emulation mode that keeps the "dormant" computer active while working on the other, so when you switch back the screen loads quickly. With all the others, it seems like Windows had to wake and "re-recognize" the device, and it took many seconds for the screen to load.The one glitch I had with this CKLau unit was with making it work with a Logitech Unifying receiver for mouse/keyboard -- I found that *IF* you have the Hotkey switch enabled, the receiver does not work well when plugged into the mouse or keyboard USB ports. It seems to block Windows from recognizing the device, gave me a bunch alert tones, and caused a USB error ("device not recognized"). If you need the Hotkey enabled, then insert the Unifying receiver into one of the USB 3.0 ports, and then it works fine. So, by keeping the Hotkey function *OFF* I use the Unifying receiver in the keyboard USB port, and the mouse and keyboard work fine. The KVM makes a LOUD beep every time you switch, but you can switch it off by pressing the following sequence on the keyboard: Right Ctrl -- Right Ctrl -- B -- Enter.Overall, feels very solidly built, and switching is quick -- highly recommended.It is a tidy sturdy switch, made of metal, works well and delivers great picture quality. One point of note, on first setting up, the displayed image over filled the screen - at first I thought this was a switch fault. I later found an image display size adjustment option on the display device, after which all was well. Easy to set up, just plug-in and use. Note that a USB power point / adapter is needed to supply the power.Plugging in a webcam to one of the USB2 ports (mouse) caused the switch to malfunction, but using a USB3 port was fine. This might be down to not fully understanding the mouse switch / hotkey settings ... which might be confused when using a combined keyboard / mouse wireless dongle.The reason for just a 3 star rating is that the product illustrations appear to show that the HDMI and USB cables are conjoined, a key characteristic for choosing this product. They are not, further the USB cable is significantly longer than the HDMI cable leading to a total rat's nest of messy cables (eight in total), requiring further expense for cable management solutions. Provision of conjoined HDMI and USB cables would give this product an unqualified 5* rating.NB: If using with closed laptops, remember to change the laptop power settings to not go to sleep when the lid is closed!!Tried all possible solutions but unable to use keyboard/mouse with the switch. Tried the latest compatible mouse but no use. Using it purely because don't have time to buy another.Does the Job as described. Solid Switch. Easy set-up. Buy it. It works... und zwar auch mit den Dingen, die man wegen "man weiss ja nicht so wirklich" vielleicht dann doch nicht kauft:Ein Monitor mit ungewöhnlicher Auflösung (3440x1440), es gibt sowohl reine HDMI als auch reine Displayport Geräte, und ein Logitech Unifying Wireless Dongle für meine Tastatur und Maus.Mit vielen vielen Kabeln, einer kleinen Kabelfernbedienung und einem Netzteil kommt der schon recht schwere und stabile Switch gut verpackt an. Sehr schön.Den Dongle in den Tastatur USB Anschluss vom KVM gesteckt, Monitor zwischengeschaltet (Grafikkarte eines Rechners hat Displayport, also mit Adapter auf HDMI, der andere direkt mit HDMI), Monitor angeschlossen (HDMI zu Displayport). Netzteil dran. KVM Switch angeschaltet. Piept einmal. Bild, Tastatur, Maus da.Die Umschaltzeiten sind sehr kurz. EDID bleibt weiterhin für alle Rechner sichtbar, d.h. kein Rechner merkt etwas davon, dass er keinen Monitor mehr angeschlossen hat. Alle Fenster bleiben, wie und wo sie waren.Nach Lesen der zwar kurz und Englisch gehaltenen Anleitung kann man einfach über Tastaturbefehle den USB Port für die Maus auf "normales" USB umschalten - an diesem USB2 Port steckt jetzt mein Headset dran und sorgt damit für zwei komplett freie USB3 Ports - und den doch nervigen lauten Quittungs-Piep abschalten.Die Quellenwahl funktioniert sowohl über Tastaturbefehle (auf verschiedene Hotkeys umstellbar) meiner Unifying Tastatur, am Gerät und mit der Kabelfernbedienung einwandfrei.Der KVM Switch benötigt zwar offiziell keinen Strom via Netzteil, sondern kann auch über die USB Ports von den angeschlossen Rechnern versorgt werden, aber ich habe wegen des USB Dongles Dauerstrom angelegt.Ob ich den Stromspar/Schlafmodus für den Dongle (und evtl alles, was hinter dem KVM hängt) noch abschalten muss, damit ein Rechner beim Runterfahren/Standby nichts unbeabsichtigt abschaltet und dann nicht mehr "da" ist, muss ich noch sehen. Bisher ist mir jedoch nichts aufgefallen. Ebenfalls gibt es keine Disconnects, die in einigen Bewertungen beschrieben wurden.Alle verwendeten Rechner laufen unter Windows 10 (H2).Negativ muss ich bewerten, dass das Netzteil mit fest angeschlossenem Kabel daherkommt. Das muss doch nicht wirklich sein - ein USB Kabel als Stromversorgung wäre deutlich sinnvoller. Denn bei so viel Rechnern hat man sicherlich einen Hub oder Rechner, der Dauerstrom liefert.Preislich liegen wir leider schon über meiner persönlichen Schmerzgrenze von 100€.Daher würde ich gerne 4,5 Sterne geben, belasse es jedoch erst einmal bei 4.Ich hab das Gerät auf Grund seiner Eigenschaft mit 60 Hz bei 4k und weiteren gekauft. Leider war mein Problem, dass drahtlose Mouse und Tastatur mit der Hotkey-Funktion zum Wechseln zwischen den PCs nicht funktionierte. Grundsätzlich ging das Umswitchen, aber beim Schreiben gab es Hänger oder oder Buchstaben wurden unendlich oft wiederholt bis man es irgendwie abbrach. Die Mouse hatte ebenfalls Hänger. Leider sind hier jedoch auch andere Hersteller nicht besser unterwegs. Es empfiehlt sich hier wohl nur schnurgebundene Eingabegeräte.