I used to think that AB's size was an issue at the 2, but he has consistently played bigger than his size. Case in point, head turning block on DWade a few games ago, and his improving ability to finish at the rim. I like it that he is strong, can really dunk hard in traffic and is somewhat fearless in attacking the rim (kind of like Rondo used to be).
Wait until there is a 7 game playoff series against a D-Wade, or...wait. Are there any good 2 guards on the Eastern Conference teams? Joe Johnson. Wait until there is a 7 game playoff series against a D-Wade or Joe Johnson, or, for that matter, any 2 guard who knows how to work the paint.
If AB's size is a limitation, that's where it will be exposed; where the pace isn't quite frantic enough to maximize his uber-motor, and the guy he's guarding knows how to score in the post.