I don't have an AA-12 but I do own a USAS-12
, its 'older cousin' if you will.
They both have the same basic constant-recoil design and weigh within a few ounces of each other so most of the traits of the USAS-12 will carry over to the AA-12, so......
They're both heavy, and I do mean heavy, 12 pounds empty and close to 15 loaded with drum magazines.
They are unwieldy, over a foot tall and close to a foot wide depending on if using a stick or drum magazine.
They have limited range, it's a shotgun after all.
Neither is quick to reload and the magazines are very bulky to carry (think of a foot long 2x4 and you've got the dimensions about right.)
I carried the USAS-12 on a few outings, and I'll be perfectly honest; the added 3 to 10 round capacity did not make up for the added bulk and weight.
Lastly, if you really, really want something like the AA-12 (and it would need a complete redesign to go from open bolt to closed) then you can always purchase a USAS-12. They run about three grand and a tax stamp.
If you just want a hi-cap semiauto shotgun, get a Saiga, it's the better choice.