I think for half pot it's an easy call, we don't have to be right that often and there value range is rather small too. With the FD bricking I'd call.

I'd pretty much be calling in this spot almost always for any size under pot unless I have a read that the guy is a uber nit.

For half pot I think we can call. He has combos of 4x,55 and flush draws. Players will float you with a hand like KQ here as well, intending to bluff if you check behind on the turn.

If he makes it pot size, I'm really not happy, but for the chance he's betting 4x and bluffing some % we can expect to be good more than 33% I would say.