AA is roughly a 60-40% favorite here, i would never limp with aces unless it was a heads up match and i wanted to throw my opponent off...thats not the case here however, so i limp with aces, im betting pot with 2 spades on the board, if i get reraised im shoving and playin the odds and wishing upon a star for the board to pair, i feel betting pot does two things, it lets you know that he has big draw if he reraises, and if he smooth calls a pot bet hes obviously just got the nut flush draw...