I recently upgraded to CS6 and so far all is great. I went from cs4 to 6 so the biggest benifit is the mercury playback engine. Being able to scrub through 1080 footage in real time and play back edits with no time line editing speeds things up so much.
However its after effects I'm liking the most. The new raytrace render engine has opened up some really interesting workflows, and I'm lucky enough to be beta testing a new 3d particle system which is amazing.
The addition of speed grade is also a very nice addition.
With apple seemingly getting out of the pro game (only updating FCP for retina display, no new features) adobe will probably get alot of new customers.Also adobe opening up the mercury playback system to certain Mac book pros will be a nice addition for those still using a mac.
Overall CS6 seems one of the better releases in a while.