I'm running Vista 64 bit and it gets better as time goes on. It was just like when windows 2000 Pro and windows XP came out. I got win 2k within the first month of it's release and it seemed like a disaster, I kept wanting to go back to windows 98 SE. Eventually, time caught up and it was my favorite windows OS to this date.
On my current system I have the idiotic and nagging UAC turned off, firewalls and windows defender turned off, sidebar and many many other Vista features turned off. I'm also running the windows classic theme. The performance is pretty good now
If I shut everything off then what's the point? Right now you can barely notice a difference between my computer and XP. Well, it's so I can have DirectX10, and to have the latest OS for future compatibility. Plus the new icons and a couple other subtle details are nice additions.
I would say Yes, Vista is better than XP. But, it requires a lot of tweaking and turning off crap. I have 4 GB of ram and somehow Vista still manages to use all of it. You need a high end system to use this.