A-K is a tricky hand, for sure. I've won a lot of big pots with it, and I've lost a lot of big pots with it. Overall, I've found that it's a very situational hand. I'll almost always open-raise with the hand pre-flop if action to folded to me. However, if there's a preflop raise in front me, I very often will flat-call to see a flop, especially if I'm in position. I usually only reraise with the hand if 1) I think I can win the hand preflop by doing so (based on reads, position, etc.) or 2) I'm on a short-stack and flatcalling would put a significant percentage of my chips in the pot. I'm also capable of giving up the hand pre-flop to a three-bet or four-bet, depending on the situation.
Example: In a live tournament I had about 29,000 chips with the blinds at 400-800. The player to my right limped, and I raised to 2,500 with A-K offsuit. The small blind than pushed all-in for 22,000. This would seem to some people like an easy call, but there were three arguments against it: 1) The player had been fairly tight, and was unlikely to make this move with garbage, 2) He looked very confident about his hand, and 3) It was a huge bet. Even if he was confident making this play with Q-Q or J-J, do I really want to put 3/4 of my stack in the pot pre-flop as a slight underdog (especially since I would still have an M of 22 if I folded)? After considering all this, I folded face-up, and the reraiser showed K-K. Like I said, it's a situational hand.
