Very thoughtful article today from VeloNews on the merits and drawbacks of the top-of-the-line electronic (Campagnolo and ShimaNO) and mechanical (SRAM) systems. Read it here.
VeloNews quickly dismisses battery life concerns ("The question of battery life is not even worth mentioning, because Di2 and EPS batteries last so incredibly long.") without providing specifics. As a long-distance cyclist, your CampOnlyGuy still wonders what "incredibly long" means--a 50-mile road race? 100 miles? 200 miles?
VeloNews, by the way, gives Campagnolo the edge in some areas (the "feel" of the shift buttons, for instance), but ranks ShimaNO higher in front shifting and the ease of "hacking" an additional battery onto the system. They also note that Campagnolo's EPS system is "insanely expensive" and weighs some 359 grams more than the cheaper top-of-the-line SRAM gruppo. (At this point, we will add our standard statement that Campagnolo will sell every single EPS system they produce, regardless of cost.)