I think Vista is pretty nice overall, as long as you have system that can handle it. I've tried Vista by a "free" copy I obtained
and can say that it was definitely glitchy with some programs I used.
Here's my reasoning behind not upgrading to Vista:
1. COST- I'm not made of money, I get like $100 a week on average at work, and ~$35-$40 of that goes to gas... Plus I'm saving money for a newer car, if I go out and spend a bunch of money on an OS, I'm down more money I have to save up again...
2. GLITCHYNESS- The version I tried didn't work with UltraMon (multi monitor program) correctly. UltraMon extends the taskbar to other monitors, well, it did that fine, but when I went to change the theme, only the main taskbar changed, the extended ones were still default. Also, it messed up the arrangement of the 3 monitor desktop I had. FOr other programs, I couldn't ever get Firefox to open up in the center monitor, it always opened in the right one. XP works where you can open a window and drag it to a different monitor and close it there and it will open again in the monitor it was closed in...didn't work w/ Vista. Overall, it just isn't very multi-monitor capable, and for me to really like it, it needs to be.
3. XP works find for my needs, so I really don't need Vista atm. In time I will upgrade, or just go with XP until the new OS comes out so I'm not shelling out money for an OS that will be outdated in not long... But I'm definitely not spending that kinda money on something I don't need.