I installed it last Saturday. I re-installed XP on Monday.
It is very pretty and the sidebar is a remarkably nice touch, but the lack of decent drivers cripples it. Not only does the new Aero desktop put extra strain on everything but nVidia (that's my card) still have really poor drivers available for Vista, meaning the desktop experience was just too slow. On top of that lots of games don't work. I couldn't find any video encoding software that would work (everything crashed), Bluetooth drivers don't work (no GlovePIE) and the nVidia drivers had no full screen video support, so I couldn't stream videos to my HDTV.
Having gone back to XP the only major differences are the pretty desktop on Vista (I'm using Google desktop for the sidebar and it's actually slightly better than Vista's) and I don't have Media Centre, which I must admit looked pretty cool.
My advice would be to wait. Probably until DirectX 10 graphics cards become affordable; that will be when the drivers will have matured hopefully
