I'm in the same boat.... I just ordered a 11-32 so I'll let you know how it goes. I'm using a mid rd (105 5701) that claims it'll handle a 30t but I've researched a little and 'seen' up to a 34t on a similar setup so I'm not too worried. Now, I didn't want to add a big brick of weight with the cassette so I sprung for a higher end sram. The weight difference between a cheap MTB cassette and a 'fancy' cassette are considerable.