Just upgraded my bike to eTap and added a 52/36 as well since I never needed the bottom end of a 50/34 at race weight. I know a lot of people will make a big deal about cadences, and how a 50/34 is fine, but really I want the 52 for that slightly quicker burst to close gaps or get up to speed descending.
I still may have to go to a 50/34, especially since I hope to do Everest Challenge.
The eTap is pretty nice so far, but all groupsets are nice on day 1.