A lot of the glitchiness was due to buggy third-party drivers. It was "fixed in 7" not as a result of any changes in 7, but as a result of third parties fixing their drivers. FWIW, I ran Vista for a year both and home and at work with very few problems. (if anything, 7 was less stable for me for a while due to some NVIDIA chipset drivers, this was eventually fixed with a driver update).
By the way, I'm definitely not saying that Microsoft didn't botch its Vista release, or that all the blame for the problems people had falls on third parties. Microsoft failed to communicate effectively with its partners, kept pulling the rug underneath them with breaking changes during the betas, etc. But saying it should have never existed, but 7 should, doesn't make much sense. If they'd held off for another two years or something and just released 7, 7 would probably have had just as much of a reputation for glitchiness as Vista did.
Agreed. If you use Vista fully-patched these days, it's perfectly acceptable. The only things you find wrong are the new UI features from Windows 7 (most noticeable the taskbar improvements).
By the way, I'm definitely not saying that Microsoft didn't botch its Vista release, or that all the blame for the problems people had falls on third parties. Microsoft failed to communicate effectively with its partners, kept pulling the rug underneath them with breaking changes during the betas, etc. But saying it should have never existed, but 7 should, doesn't make much sense. If they'd held off for another two years or something and just released 7, 7 would probably have had just as much of a reputation for glitchiness as Vista did.