just some initial thoughts from my perspective:
1. Gallery loads up with no lag whatsoever on gb rooted rom
ex. try changing the wallpaper with wall from sd.
2. power off and on are under 15 seconds. maybe under 10 seconds. must go into a hibernate mode. Very nice. reboot takes the same time though.
3. stock browser seems improved a bit, slightly faster rendering pages but it could be placebo effect.
4. Sense is running very quick, probably a tad quicker than in froyo.
5. flip sense clock on gb
6. 3 options for people widget now, full, half and 3/4 screen which is a nice
Those are some differences thus far. I like the new ota. wish sense 2.1 was added as well but you take the good with bad. Hope this helps.
btw, thanks Karle for the link.