Well, I don't have 6.0 but then I still have the "new car smell" with CS5.5.
Honestly, I couldn't justify upgrading PS at the rate Adobe releases these versions.
I did jump from CS3 (a perfectly fine version) to 5.5 for the native 64 bit processing but otherwise not much else.
However, I really dislike how Adobe ties ACR updates to CS releases. Lo-be the person who buys a new camera model not supported in ACR mid CS release and has to buy the newest PS to get ACR for RAW file processing.