And, here is the Air France premium economy seat size chart:
http://www.seatguru.com/airlines/Air.../fleetinfo.php

Basically, they are removing seats in order to increase the seat width. Delta is only increasing pitch, and not nearly as much as AF.

38" pitch, and 19" width is not too bad for the TATL flights. That actually is better than the domestic Delta First 763 product, which is often used on 4-5 hour flights in the US.

In summary, I don't think there is any argument, and that the AF premium economy seat offers more pitch and more width, compared with Delta EC.