The people who complain about Vista never used it for any sufficently long time to be able to comment.
I used it in a dual boot system with XP. Vista after SP1 was perfectly fine especially on a reasonable desktop like what I have,and I tweaked it too. To this day I am not sure why people have to keep on egging on Vista -its almost like they dug themselves into hole about it.
The worst thing is that Windows 7 is basically late model Vista with better memory management,improved SSD support,better out of the box optimisation,other tweaks like less intrusive UAC and a couple of years hardware advancements,and vendor driver improvements. A lot of initial problems with Vista was since MS moved to a new driver model,which people like Nvidia did not follow to a tee,which caused problems,and that fact that many Intel IGPs were subpar for the OS anyway. The recommended minimum spec for Vista was too low.
When I moved over to Windows 7,it was an improvement,but honestly it was not as magical as people were saying.