I've had a Belkin OmniCube KVM switch for a good 5 or 6 years now. It's been perfect. Never a glitch, and less signal loss/degredation than the old manual switches, too.
I don't run the mice through it as I use a USB mouse on the PC. But keyboard and video have been switching between Amiga (or, currently, SGI) and PC for the entire time I've had it.
I can't speak for others, but mine has been 100% reliable, and though I cringed spending that much for a KVM switch, it's turned out well worth the money.
