I would say the double flap definitely have it's pros and con. Let me start off that I'm a big bag girl so the weight of it doesn't bother me at all. I certainly love the idea of the double flap because I do think it's more organized and what not. I guess i'm just not used to the very boxy look, it certainly looks more full and short (length wise) compared to the single flap (my sister have the single). I'm also very petite, barely 5'3 , so I do find that it might look a bit boxy for my shape.I just got the exact same one, it hasn't arrived yet. So you're not liking the double flap? What about the weight of it, is it bothering you at all?
I've noticed that things can roll out of the bag if you bend over wearing the bag in any single flap (even the boy). My lipstick went flying across the room the other day slipping out of the corner of my boy. Maybe the double flap is helpful for the reason but I can see why it would also be very cumbersome to flip daily, maybe we just get used to it after some time. It certainly looks pretty!