Indeed the synchro shifting works! It was well confirmed before the build that the Ultegra 6770 drop shifters would work with the XTR derailleurs, but there was some uncertainty as to whether the bar display and syncro shifting would work. It turns out to work great. I've made two shifting maps, one for climbing and one with a tighter map for the flats. Each has different shift points on the way up and the way down. As you transition to the top of a set, the bartop display beeps to let me know the next shift will involve a front (and rear) shift. When it changes rings, I have it set to move the rear one or two steps along with the front change such that the transition maintains a cadence. One great thing about it, is that I have wide out-of-spec chainrings, and the syncro allows me to not worry about cross chaining into a gear that will exceed the chain length large-to-large, or exceed the chain wrap small-to-small. I also love the gear display for the couple second after each shift. No more looking back to see what gear I am in.
Last edited by Turbotandem; 03-20-16 at 10:25 PM.