Just installed the new card. These results are by no means scientific, but an indication of initial improvements.
TW: Shogun 2, on Sekigahara, used an initial cavalry, infantry archer fight in woods (early move of the battle):
With XFX 5770 1GB (settings mixed between Ultra and High): framerates zoomed in on the fight were around 13-15fps
With MSI TF 660 (all settings maxed out): framerates zoomed in on the fight were 45-50 fps, very smooth
Skyrim, Labyrinthine with Ice Troll fight, flame atronach, Lydia
5770 (settings on ultra for the most part, a few were lower, very little AA/AF): framerates around 32-37
660 (settings on Ultra, 8x AA / 16x AF): framerates remained pegged at the Skyrim cap of 60fps. Looks great.
Overall, card seems to be no louder than the XFX (again, subjective, not scientific) as the 212+ CPU fan is the loudest component (fan speed is bottomed out, think it is running at 900 RPM).