I know of the issue with reduce 2D performance your speaking of, and it seems to occur on every system I've tested with drivers later then the 27.10's, but from what I've seen it isnt very severe as there are exceedingly few applications that truly stress 2D graphics performance anymore... so the relative performance decrease has gone pretty much completely unnoticed by most people unless you actually run 2D benchmarks to test it.
Certainly on my own system I do not even remotely notice any decreased 2D performance unless I actually run 2D benchmarks, and those will reveal a dramatic performance drop.
The only areas I've yet seen in which it's truly noticeable is when doing some 2D graphics design at 1600x1200, or when driving two monitors from one card in high resolution.
It's a definite isue with nVidia's latest drivers, but I've not seen many instances wherein the reduced operformance is so severe that it's noticeable to the end-user as seems to be the case for you.
For whatever reason the issue seems unusually prevalent on your system..... a hell of a lot more prevalent if it's so poor that you actually find it to be slow merely minimizing windows etc.
