I'm going on a 2,000 mile round trip soon and I'm not sure if I'm going to upgrade to 8.0 beforehand. I have just heard of too many little issues with Autopilot on 8.0 and I'm happy with the way it is working on 7.1. For that long of a trip, I don't want any drama.
However, if charging is faster with 8.0 (better taper profile),I might have to bite the bullet.