The only real problem was my beloved Combat Flight Simulator 2 game. When we got the new Vista laptop in 2008, I'd hoped its faster components, portability, and 4MB RAM would be an improvement over our 2001 1MB RAM desktop's game performance problems. Much to my chagrin after the purchase, I was warned not to try running the game on Vista. So I haven't, and it's been a real bummer, esp. since I struggled with whether to order the laptop with XP or Vista in the first place, and had waited for MS to get most of the bugs out of Vista and put plenty of RAM aboard to handle it.
Otherwise, once we got used to Vista, it works fine for us, with none of the common issues people originally griped about.