Recently we just upgraded a customers Lynskey Green Monster frame from Shimano 6600 Ultegra to 6770 Ultegra Di2 (Digital Integrated Intelligence.) Also, we dropped weight by removing his rack system, and replacing it with Revelate Designs frame bag and saddle bag.
This customer trains for ultra long races like the Race Across America (RAAM), so an average training ride is +10 hours. What the customer noticed after taking it for a long ride last weekend is that total weight of the bicycle had decreased, shifting is consistent from start to finish, and Ultegra Di2 is less fatiguing on the wrist, since Di2 shifting is at a push of a button instead of a throw of a lever.
If you look closely at the rear wheel there is indeed a 11-34 XTR cassette installed. How did we do it?