I actually didn't know if I would like the double flap either, and while I have yet to see the Maxi, I can actually see the argument in both sides. I actually like the double flap and the extra compartments on the inside, because I mean for me part of my love affair with Chanel is in part due to the stories behind all the pockets in the m/l but I find that one too small for me so now I kind of feel like Jumbo and Maxi have the same story you know?
I just got the grey single flap maxi and I like it because it's *less* structured, a tiny bit soft and floppy (mind you, this is all relative, it's still a Chanel flap, after all). Might also have something to do with the leather - the 10A grey caviar (which I have in the maxi) is much shinier and softer than the black caviar on my jumbo (also a single flap, bought in October). I'm glad I got a floppy single flap maxi, so when the double flaps are out in full force I can get one and not feel guilty for buying the "same" bag twice!