My wife has a 1 month old desktop with Vista that she runs a lot. We have had a few issues, but largely due to differences in ways to get to somewhere else compared to previous O.S.'s. The worst thing I can say about it so far is that it's doing okay; the best thing I can say about it so far is that it's doing okay.

We went ahead and upgraded to Office Vista. I think you can say that you are more likely to have issues if you try to run a lot of older XP (or esp. Win 98) programs and hardware items on a Vista machine, potentially a source of major compatibility issues tha may be very crippling.

This is the 21st Century. Don't try to run 20th Century stuff on a 21st Century computer. It makes as much sense as putting a 2 row corn header on a CIH 2388.

If Vista and new machines just offer you lots more options and horsepower than you need, buy a refurbished or secondhand XP machine.