Pros: Versatile: your hands-on input devices can be USB or or PS/2. Your remote systems can be USB or PS/2. You probably will not need the (not included) A/C adapter.

Cons: No audio switching: Unlike newer IOGEAR equipment, this unit does NOT have audio in-line switching. Was not a deal for me at all, but it's a feature people might incorrectly assume is present.

Other Thoughts: Con for me personally: this unit would not work with the oldest of my 3 systems: a vintage 2002 Dell Dimension 8300. Consistent "keyboard failure" during Power-On Self Test. I could still use the USB KB to change BIOS settings on the 8300, but after boot, only the mouse (and not the KB) would be seen by WinXP.

Solution was to scavenge an unused 5V A/C adapter from another IOGEAR setup. Problem went away. My USB keyboard now stays backlit 24/7, but whatevs. If I didn't have a machine this old, I probably wouldn't have this problem.

So I can't really ding IOGEAR about it.

Manufacturer Response:

First, thank you for choosing IOGEAR. Please contact our customer support at 1-866-946-4327 / email us: support@iogear.com. and refer to this post. We would like to discuss this further with you. Thank you for choosing IOGEAR!

Pros: Well-built, compact metal enclosure, supports old as well as new computers.

Cons: Cable sets use unique proprietary 15-pin connector on KVM end, not convenient to extend. The real problem seems to stem from the 15-pin limitation and the need to squeeze USB and PS/2 connections as well as VGA into 15 pins, they seem to have dropped the VGA data channel, so now my computer sees the monitor as a generic monitor, and refuses to set its resolution to anything finer than XGA (1024x768)

Other Thoughts: The unit comes with four cablesets, two of which are about a foot longer than the others. Even so, I found I had to go find USB and VGA extenders to reach one of the machines under my desk.
I had one real head-scratcher: my oldest system, a dual-PII on a Gigabyte motherboard, would not power up when connected to this switch via the PS/2 connectors, but boots up fine when I connect via USB.

Pros: Works like a charm for both USB and PS2 devices. Has been flawless on all OS's tried, including Linux of many vintages, Win98, and Win7 Pro.

Cons: None

Other Thoughts: Comes with a single USB plug that provides both mouse and keyboard input to the computer, and the standard separate PS2 style mouse and keyboard plugs, and then the VGA connector, bringing the total connectors for each computer to four.
If you need the USB, then the PS2 connectors hang free (disconnected). If instead you need the PS2, then the single USB hangs free.
Tapping the scroll-lock key twice, followed by the number of the computer (1-4), and then the enter key causes the switch. After tapping the scroll-lock twice, the numeric lock and caps lights flash to tell you that the KVM is ready for the number and enter keys.
The box also has a set of switches for manual press control that include a yellow light that illuminates for each active (powered) computer. A green light will also illuminate next to the yellow light for the active computer so you can tell which computer you have selected.

Pros: Affordable and has both PS2 and USB connections at "client" side which is good as the PS2 hardware is still around but fading ... I use it on my "workbench" to connect the equipment being tested, analyzed and then fixed. Also to suck off the files before I do any potentially damaging intrusions into the "under repair" computer.

Cons: Puzzled that it didn't work right out of the box ... but, after glancing at the User Guide, and powering all connected systems off; then, back on again = it WORKED! Was also puzzled that it didn't come with a power supply -- I surmise it gets it's 5vdc juice from the target computer's keyboard connection.