It can't be said enough. Microsoft Vista is an abysmal failure. It went for glitz at the expense of performance, and while it does provide some additional security, the performance trade-off was horrible.
It's a huge resource hog. Oh, it did some things right, such as foisting some of the Aero graphics processing off onto the graphics card. On the whole though, it's a horrible piece of bloatware. Ugh.
Windows 95 was clumsy and annoying. Windows 98 was a bit better, and Windows ME was a horrible piece of junk. XP was no work of art, but it was at least usable. Vista, on the other hand, is a piece of garbage.
Yeah, I know it's been fashionable to bash Vista. That happens for a reason, though. It's because Vista stinks.