I was warned off Vista when I was about to buy a new notebook. Got XP, but guess what? It wouldn't install - would not recognise the HD.
I took the PC back and the company did some checks and found that my notebook was designed for Vista only, and would not take XP.
So I installed Vista x64 - and I'm pleased to say I haven't had a single problem in the 3 months I've had it.
My desktop PC needed an upgrade, and I bought new Vista-compatible hardware based on suggestions I'd read over at the AGW H/S forum. I opted for the x32 version this time because I had had ONE driver problem on x64, and was worried in case of later problems. Same deal - no problems with Vista at all, and I am very happy with it.
However! I had been using Trend Micro anti virus. This no longer worked with Vista SP1. TM were very unhelpful, so I purchased a new AV package - PCSecurity "The Shield" - works really well.
The only reason I can think of for dissatisfaction with Vista is because people have installed it on legacy hardware. From what I've read on AGW, that was never going to work.