The new format is ridiculous really. Platini and his jackassery.
Groups E and F winners are theoretically at a disadvantage in the first knockout stage because they meet second placed teams. Other group winners meet third placed teams.
Winning Group E (or F) is effectively the same as coming second in Groups A or B. You get a MUCH harder road in the knockout stages if you come out of Group E or F.
http://imgur.com/25DsW8V - image showing the simulated probability of winning from the six different groups in the EURO 2016 (Teams from group E has an approximate 28% less chance of winning than teams from group A).
Group A has the best outcome from the simulations, which could also be seen from just looking at the playoff-structure (the winners of group A) move on to face runner-ups in the quarter-finals.
France is automatically put into group A.