i suck. underpairs suck too.

[Wally Weeks]

That's true, it may or may not be scary.

I think that the context defines whether or not the A pairing the turn is scary. Perhaps if your opponents have seen whether or not you've been raising with high cards plays into this. If your opponent has seen you preflop raising with A-high hands, he may muck a bottom or middle pair HU even.

Either way, I have a hard time not seeing a reason to fire on the turn (given the action up to this point) with position and taking a free showdown regardless of the results. If he checks the turn, he'll have to muck the showdown. Why not fire the turn and give your opponent even a small possibility to muck the turn to take the pot down? And since we are in position we can either muck the river if bet into or take a free showdown to see if we have the best hand.

I think this is the best line. Either way, our opponents will see that we don't always raise or bet into the pot with an A.