If your playing Axs with the intention of showing down your pair of Aces unimproved on the river then it will defnitely be -EV. I play this hand for nut nut flush potential, 2 pair, or 3 of a kind only. Otherwise I'm taking one stab at a flop w/ an [Axx] flop and/or if I'm in position (its about 33% less likely that someone has an Ace if you have one).