[Stylite]

Buzz,

While A2 may be a statistical favorite compared to AJ against much of the Sb's range, much of the time it is only a slightly better option than AJ. Playing AJ in those cases would only be a very small error. However, against the lower aces, playing A2 is a substantial mistake.

The only hands where A2 is clearly superior (greater than 7% edge) to AJ is against AQ, AK and a slowplayed big hand like two pair or a set.

All in all, its pretty close depending on the read. If we can rule out the slowplayed big hands and still go with A2, approximately one in five times (very rough estimate) you'll be placing yourself in a dominated position while 4 in five times you'll be slightly better off than the AJ. If you choose AJ you'll usually be a favorite to win the hand, but 4 out five times a few percent less favored than if you had chosen A2.

I'll have to put some more thought into this situation as you have brought out some aspects I originally didn't consider. In any case, I'm still confident that whether you go with A2 or AJ, you are more than likely in front of the Sb after his check/call and should be extracting value (though not with reckless abandon).