Hi Folks,
Back in July I picked up the L1 KVM (4 comp / dual mon / 5G model 1.4 Display Port KVM Switch - Dual Monitor - Four Computer.
Naturally, it took me over a month to finally get it hooked up 
Very nice unit; hefty beast. Works great. It’s been interesting to see which computers work well with it. Gotta be something in the combination of bios/usb controller. I say that because I use both a mouse and trackball interchangeably.
When plugged into the KVM:
On computer 1 (the newest) the mouse works before the OS, not the trackball
On computer 2 the trackball works before the OS, not the mouse
On computer 3 (before the OS) the trackball works if plugged into the HID port on the front IO (not the back), rather than into the hub I usually use.
Computer 4 isn’t used at the moment (cables are hooked up and waiting)
And yes, I did experiment with all the various combos.
In case your wondering, none of this is a complaint. It’s just the weirdness I’ve come to expect from computers.
If I was going to be nit-picky, a power button would be nice. Seriously, why does this get left off so many computer gizmos??
Oh, and maybe an inch or so wider to make it easier to plug things in (albeit, once hooked up you probably won’t be messing with it).
Other than the weirdness, I like it. Buy it again? Yup.