I've had Vista since day 1, and i've never had any problems with it.
I'll be the first to admit driver support used to be shaky, and the was an initial performace drop on XP, but now, its stable, I have far less crashes than I did on XP, and the new memory learning features of Vista actually make programs load faster.
I do believe you have to have a system for it. I run, AMD Phenom 9850, 8Gb Ram, GTX 260, so i get fantastic speed on everything. But as an OS I love Vista, and i'll move on to 7 when it's out too.
I see an argument on similar scale to this in the flight sim community, between FS2004 and FSX, but even though the newer program has less support, and more bugs, its the future, and will be improved, whereas the older one will eventually be dropped.