dave can correct me if i'm wrong, but i dont think there are any changes from 2010 to 2011 that will effect shifting performance at all. i have the current version of chorus-11, and it performs flawlessly, shifting is precise and required significantly less effort than my 10-sp stuff.

i would imagine that with the introduction of the updated 2011 changes, the 2010 stuff should be reduced in price, if so - thats the direction i would go in for the savings.

re: single or dual pivots: doesnt matter, IMO, you'll adapt to either.