when they push back on the turn

[detruncate]

Party Poker 2/4 Hold'em (6 handed) converter

Villain is largely unknown. He's shown both pre- and post-flop aggression in the hands I've seen him play, betting into a few scary boards... but I don't know whether he had the goods.

Preflop: Hero is BB with A[img]/images/graemlins/diamond.gif[/img], A[img]/images/graemlins/spade.gif[/img].
UTG calls, <font color="#666666">1 fold</font>, CO calls, <font color="#666666">2 folds</font>, <font color="#CC3333">Hero raises</font>, UTG calls, CO calls.

Flop: (6.50 SB) Q[img]/images/graemlins/spade.gif[/img], 7[img]/images/graemlins/diamond.gif[/img], 4[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets</font>, UTG folds, CO calls.

Turn: (4.25 BB) 2[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets</font>, <font color="#CC3333">CO raises</font>, Hero ???

These sorts of situations come up a lot -- even semi-aggressive players seem to like to take a shot on the turn. The board isn't scary, but raising risks a 3-bet if Villain has a strong hand, and he might give up if he's bluffing. On the other hand, if he has a good but not great hand I'm going to get an extra BB and possibly discourage people from taking liberties on the turn.

Is it better to just call down from here? Do we lose more from action or inaction?