What I like about Flying Blue is that there is good rewards availability (eben for one-wat flights) and they don't include fuel surcharge on the reward ticket (unlike LH, OS and other Miles & More carriers).
However, while Eu flights are good for status, earning miles on the cheapest has become painful. Some AF flights even earn 0 miles in certain booking classes, or you have to pay extra to earn 125 or so...
Plus, I hate the fact that one has to pay extra for checked bagage on most intra-european AF flights, as if it was a LLC.