The thing about Di2 is that if you crash or otherwise damage one of the cables, it can be a fairly elaborate and expensive repair. I helped my lbs troubleshoot the aftermath of a crash on a Di2 system. I recall it was going to take $400 in cables to fix it, and the diagnostic software didn't pinpoint the issue very quickly. OTOH, I have seen any number of cable driven bikes that were modified into single speeds so the rider could complete their ride. Di2 failures among randonneurs that ride a lot seems to involve not charging the battery in time. Oftentimes the battery is hidden and you can't just swap another one in. It seems like etap wouldn't have this problem as much because you are constantly swapping out batteries. I wanted an etap system for my travel bike, but now they went to 12 speed and I see no reason for that. Maybe shimano will come out with wireless