I got the 4x4 usb 2.0 version. I have connected a powered usb hub with webcam, headset, multiple mice and keyboards and it works great.
The only problem is that it acts up once every few months. I have to unplug all cables from the computers and all 4 ports so it reboots. Then it works great. Using microusb port on the front to power it caused instability.

Kind of expensive little device. I paid $150 for the GUS4C2. I kept looking at these KVM switches but most if not all had a disclaimer that they did not work with docking stations. I almost bought anyway once or twice, then this showed up stating it s fully compatible with docking station and switching between two computers.
I have a Windows system, two laptops while one is for work. Formally I had to change the USB-C from one computer to the other and switch the USB for my pen tablet as well. Not a big deal but a nuisance and doing it twice a day, I thought there might be some additional wear and tear on the wires.
Reluctant purchase, is working out great. There is a little button device you plug in ass a remote. Just press the button and the docking station will switch to the other computer. There is a light on the port switch device itself to display which computer is on (#1 or #2). It does successfully switch other USB devices that are plugged into the port switch. I am using display ports for two monitors.
Ultimately it's an expensive luxury but certainly glad I have it now. I can switch back and forth from home to work with a single and no rearranging wires. Once in awhile my monitors might get interrupted but I think that happens anyway without this port switch.

I got this to switch the mic on my Astro a50s between my PS5 and my PC and it works well for that so far but I have some issues with how the device's input layout, predominantly the external power input being on the front of the device and the button to switch inputs being feed from the back of it. In some setups I'm sure this is fine but I feel that the majority of people will want the switch to be connected to the front and the ability to connect a dedicated power source in the back of the device. Also $40 is very steep for a usb switch that has an 8 year old design with no USB 3 compatibility and while IOGEAR does offer an newer version that one will run you $80 which is frankly unacceptable and I am lucky I did not need this for a USB 3 device. The build quality also feels middling for a $40 item, with the worst part being the button's cable, it is very thin and feels like I could accidently pull it out or rip it most cheep wired ear buds come with wires that feel strong than this switch which is the only way to switch outputs so if this cable breaks you are out of luck as there is no switch on the device it's self. The one reason I bought this over cheaper options is many of those $20 dollar usb switches seems to have no room for electrical protection and thus might short out the devices you have hooked up to them and several reviews back my theory on those cheaper switches up. I really wish companies would make this type of switch in a 1in to 2out or 2in to 2out configuration as I don't need that many slots. Overall I would recommend this only if you don't need USB 3 compatibility AND want to play it safe with potential the devices you hook up, really want/need a device with a wired switch, or if it goes on sale for less than $30.

Simple and easy to set up, takes less than a few minutes to start using, effective switch.

Pros:
- Clean, simple packaging
- Removable USB 3.0 Type B Cables, of which are an appropriate length to plug in nearby computers
- Removable 2.5mm switch button that can be replaced if it breaks
- Low profile design, computers and switch plug in on back of unit, USB devices plug in on the front
- Micro-usb port for powering devices if needed
- No fuss setup, plug and play

Cons:
- Have to manually cycle between all 4 PC's 1-by-1.
- LED indicator for the selected port might be difficult to see if the switch is far away from you

It was hard to find a real con to this unit, it does exactly what I need it to do, and the minor inconveniences of having to click the switch button a few extra times is not a big detractor to the overall performance. A slightly better indicator LED design would be preferable, but isn't a dealbreaker.

Since I couldn't find a reliable and reasonably priced HDMI KVM, I decided to use the multi-HDMI/DP ports and input selection on my monitors. That just left input switching, which is where this product came in. There really don't appear to be many competing devices of this type, so I was hoping this one would perform well.

Pros
The device appears to be well constructed. It came with 4 A/B USB3.0 cables, which is nice).

Cons
For my arrangement, the included A/B cables weren't long enough. That's not really IOGear's fault, but it's hard to imagine many setups where the included cables would work well. I purchased some 9 foot AmazonBasics cables (https://www.amazon.com/dp/B00I83XF76/ref=cm_cr_ryp_prd_ttl_sol_22), and they work great. This is not going to be a con for everyone, but I would have preferred if there was a way to toggle the port selection with a key combination. The included button is ok, but coming from KVMs, it would be much nicer to just hit Scroll Lock (or some other key) a couple times, and then an arrow or number. That's a bit more involved than just switching the traffic (since you're having to identify HMI devices and snoot their input), but I would have been ok with having to use a specific USB port on the front of the switch for my keyboard. The last gripe is that there's no option to supply your own power to the switch. the USB3.0 standard allows for higher draw, but it's still a single USB3.0 port having to service 4 at the switch (along with whatever amount of power the device itself may use).

Conclusion
The only things I don't like about the product are things I didn't expect out of it in the first place. If the product had longer cables, or more traditional KVM functionality, it would have cost more. It just so happens I would have been willing to pay for it, but I'm probably not the target audience for the product in the first place :p