I think the A7 is a real winner, and it's priced well, too. The only think I didn't like was the dash...it looks empty. I think replacing the pop-out navigation with a standard one that's always visible would be more attractive. It may not look as "futuristic", but I think it would look better.
The E-tron...I think sucks. It looks like an uglied up R8. It performs worse than the R8 V8, and I think it will get murdered by the R8 V10, which is in the same price range. And there's always the hassle of dealing with "what ifs." "What if I only have enough juice for 20 miles of driving, and my home is 25 miles away?"