Things I like better on Windows 7 than Vista:
UAC - The now famous User Account Control that was waaaaay intrusive on Vista, to the point I turned it off altogether, is "tamed" in W7.
Taskbar - I always overuse the browser
and with the W7 taskbar it's a little easier to hover over the taskbar icon and see the window I want which brower window I one I want to select.
The fun part is that I don't have anything that "needs" even XP. Windows 2000 runs fine
I hated Vista until I turned UAC off and Service Pack 1 came out.
Since Service pack 1, it would no longer try to index my hard drive every time I clicked on drive C:
The most subjective thing I like about windows 7 is some sort of philosophical admission of guilt that yes Vista was screwed up,got a bad reputation and since we (MS) fixed it the only way to get away from the stigma is to introduce a "New" operating system called Windows 7
Obviously, like the XP crowd, if Vista is what you really like there is no real reason not to go back to it, if the effort is worth it to you.
You've run both one the same machine so you have first had experience if the machine was more "snappy" with w7 than with vista.
Like with most things MS changes, it OK if you were never used to something else before.
NT4 was fine for me even when "computer guys" (used to windows 3.1 and windows 95) kept saying how "hard" NT4 was to work with.
What version of windows were you running before the new machine ?