Originally Posted by
Koyote
etap is truly wireless, which is nice. Di2’s advantage is that you only have to worry about one battery - and it lasts a long time on a charge.
True. Though I discovered one downside. I once had the Di2 battery in my seat post shaken loose during a long ride over some particularly rough gravel. Without tools, I was unable to fish the wire out from the seat tube to reconnect the battery and so had to single speed home. I suppose an eTap battery could get rattled loose too, but I carry a spare and can easily replace it.