Hopefully with sub compact chainrings, I will not need to go down the MTB cassette route, but it is a useful option to know about.
I have a number of bikes I am thinking of stripping and considered using the group sets from. However I would like to keep compatibility of the wheelset with my Titanium Reilly which has 10s Force, so that rules out a Campag setup, (as well as the curse for mixing Japanese with Campag). However swapping a cassette is not a big deal if I fit 11 speed.
I will need to buy good used shifters and mechs to go with the existing Ultegra 8000 crankset. I don't want the shifters with cables out the sides, so 6700 seems the way to go in the Ultegra range and Duraace is too expensive.