My most typical route on UA is the 961/960 CDG-SFO and I have never seen E+ on a single flight. My last two flights were routed via IAD, so perhaps they are finally using E+ planes of the direct route. Basenji did state that the last (if ever) planes of the fleet to receive E+ would be the trans-Atlantic routes to the West coast. That was some time ago, though.

Anyway, whatever you decide, have a good trip.