I am about to move to a medium cage rear mech 11-32 cassette from a short cage and 12-28.
The climbs in Northern Cyprus require this. Yesterday I was riding with a guy who is thin as a rake, fit as you like and works for Felt product development. He was on the new 2015 carbon felt bling machine with electronic shifting etc...he was flying up the climbs, i asked him waht cassette he had, and he had an 11-32 fitted for these rides. No wonder he was flying. Ok mostly its because he's super fit and light, compared to my kinda fit and heavy, but neverthe less it was re assurring to know that actually an 11-32 isnt 'super big', and ther eis no rule that sayeth you have to wreck your joints with smaller cassette.
Info i kindly got on this forum and from bike shops was that a medium rd6800 ultegra mech with 11-32t works.