England's Road.cc online magazine published a story describing their first road test of the new EPS system, and their review is generally positive. They report good shifting, including a nifty feature that aligns the front derailleur when you shift gears on the cassette. Cons include high cost and a slight weight penalty.
They didn't mention the fact that electronic shifting relies on batteries, which run down. However, the article notes,
"... if the worst happens and you do manage to break it out on the road, you can manually put it into the gear you want and it’ll stay put."
Manual shifting. What a concept. And of course, if your dead battery forces you into manual mode, you'll need to stop and get off the bike every time you want to shift (back to the 1920s) or stay in the same gear (back to the 19th Century).