I'm kinda confussed by your post...

You mention issues with the NVIDIA cards, series 6 and 7... yet your specs have an ATI...

I have a 6800GT OC and far from the slow load times when switching views, I have no issues with my C-130. I have the latest drives, I run a P4 2.8 2GB.

PCIX is a new technology, and of course it'll have issues, just gotta be really patient with it and be very handy with the BIOS Updates.

If I had the money, I would go PCIX right now... That project will have to wait at leats a year... and with that FSX....