The biggest negative on AF is that you have to connect through CDG. AMS is a much easier connection point in Europe.

I'd also consider the nonstop on AZ (assuming you're going to MXP; if not, never mind), even though the J isn't quite as nice. I don't know how bad it would have to be (maybe OK-style) before I'd think it rated an extra connection and the shorter TATL segment (less sleep). Of course, you could also fly backwards and conenct via DTW, though that would mean an earlier start to your trip, but a longer flight TATL than BOS-Italy.