Let me talk about the hardware I just bought.
New KVM Switch
First, there is the Belkin SOHO OmniView 2-port DVI/USB/Audio switch. I am so unsatisfied with this. Now, let me first disclaim that I didn't buy enough cables, so I don't have the second DVI plugged in right now. Maybe there's some kind of voodoo there that would fix this.
When I have the KVM switch plugged into my workstation, and it is set to that computer... the computer will not boot. It won't even get to the BIOS screen. When I set the switch to the other machine, the first one will boot. That second machine has no such problems. I'd guess the Tyan BIOS can't cope with what I see in my linux logs as device descriptor read/all, error 2 and config descriptor too short (expected 59, got 43), but that's just a guess because they don't show up in the logs every time.
Then there's the keyboard support. AUGH! Now, I have to mention that while I have several AT keyboards and tons of PS/2 keyboards, I have no USB ones. So I'm using an adapter. So it might be that my Belkin KVM won't play nice with my Belkin adapter.
At any rate, the keyboard is really something. There's like 500ms lag between pressing the first key and it appearing on the screen. The keyboard repeat rate is *wrong* and cannot be fixed. Holding down a key does not show up to the computer as a key being held down, but instead as being pressed repeatedly, at a slow rate. Like those old "turbo fire buttons". This makes games impossible, since you hold down a key to move, and the movements are in short, separate bursts.
Then there's the lag. Type a sentence, and perhaps 5 seconds later, it will finish being typed to the computer. Maybe it'll even have all the characters in it. AUGH.
So, right now, I'm using my monitor to switch video (need another DVI cable), my new KVM to switch the mouse, and my old KVM to switch the keyboard. Not really optimal. I did see on macosxhints some guy with a different problem (no keyboard at all), and his fix was to plug the keyboard into the extra USB ports on the switch. This actually works, but since it's not doing its keyboard magic, the KVM shortcut keys will no longer work. If I get another cable, that'll be the stopgap solution. Then, depending on when they're open, I'll call Belkin and see if I can't get an answer out of their tech support.
New Geforce FX
Then there's my new Geforce FX 5700 Ultra. Usually within the first minute that I start X, there will be a short flicker in the display, showing a band of garbage (or maybe just some other video memory) on the DVI port. This happens whether or not I'm using a DVI->VGA adapter. The flicker will repeat at random intervals as long as I'm running X. I haven't experimented too much with fixing this yet, because I've been busy with the KVM. But I have poked at the NvAGP settings, the AGP drive strength, reducing to 2x speeds...
I guess they haven't got the driver 100% with 2.6 because it floods the logs with messages about sleeping during spinlocks every few seconds. This seems to be a common problem, and the current solution is to turn off that particular error reporting in the kernel.
Also, sometimes the machine locks hard when coming out of xscreensaver. With the matrox card, it would lock hard during xscreensaver. Maybe xscreensaver just hates me.
Anyway, that's where I am now.