I had two complaints about Vista, though my machine is really too low to be running it. Creative drivers never seemed to get surround sound right. They crash and cause problems with my XFI gamer card. Video did not play as well, especially Quicktime. It works much better back on XP. With a computer capable of 64 bit processing, I would likely have been fine. If they had left it the way it was at points in beta, it would have been fine...
Also, my speakers emit a popping sound at about a 80 pops/second.
My speakers and mouse are 5 years old and came from my old XP machine. Neither problem existed on my old machine.
My wife went through hell on printer drivers for Vista. It seems HP collaborated in the creation of Vista to make sure people had to buy new printers.