While this is very player dependent, a lot of times I like capping with AQ on the turn. CO could be raising a weaker queen here or AQ as well, allowing you to either push him off his hand or win more money. The reason why I say CO could have a weaker queen is because many times, players will 3-bet KQ here in position and check behind you on the river if he fails to improve. It costs the same as calling you down, but can also cause you to fold a better hand.

Of course, it is possible CO does have a set. Therefore I like capping the turn and bet/folding the river or calling the turn and bet/calling the river.