Hey guys! When I purchased a CAAD 9 three yrs ago, I immediately upgraded the components to Ultegra 6600. For the past year or so, I began switching components to SRAM (Red crank, Force front derailleur). Last week, I was lucky enough to win a bid on a Force shifters.

My question is, do I go with Force or Red rear derailleur? Is there a difference between the two in terms shifting?

Thanks.