I purchased a CPU upgrade for my main machine, and I'm awaiting UPS now (it should arrive today). Since I've been finding myself seriously CPU-bound lately, this should help.
Just for kicks, I tried putting my flashed GeForce 2 MX back into the computer. To my surprise, it worked fine. I'm guessing that the driver in the ROM on the card is just no good, so the installer didn't want to work with it, but the driver included with Mac OS X works just fine.
So, I get Quartz Extreme again, too. What an unexpected surprise.
When I get a new machine (probably sometime this summer) and this machine becomes the new geeklair.net server, I'll probably put the original videocard back in (I suspect it uses less power - and the less hackish the server is, the better).