I got my Synapse today and I think I'll love it as much as my other bags...
But...
I'd really like it about two inches longer and the back compartment about two inches wider (maybe 1 1/2). That way, my cache would fit in nicely and I'd still be able to pack in all the extra junk I take when I travel. Plus, if it were two inches longer, I might be able to get my small water bottle into one of the front side pockets.

