Vista great, but i dont think x64 bit version is worth it really. If your a casual computer user or even someonelike myself who plays games, internet, music composing etc, i had some problem finding 64bit drivers for certain things. It was the final straw when my printer had no 64 bit drivers. Personally i dont think they should make 2 differnt bit versions of OS anymore, then programmers can focus on one set of drivers per OS.
A lot of people **** off VIsta but theres nothing wrong with it, and ive had it pretty much since it hit the shelves. Windows 7 doesnt look too differnt (at this stage) to vista. It depends on what the gripe was initially, security, drivers, UAC etc.