I think check/fold is a bad idea, check/call (to induce bluffs from busted FD's obviously) or bet/fold (get value from a Q) are the best options. If he bets it's not a block bet, it's a valuebet. $180 looks good.

Is this a strong player? If so, I would expect him to raise you either on the flop or on the turn with a flush draw, especially if you've been playing very laggy. I never expect him to show a set here. If he's this type of player then he may well have a weak made hand like KQ or TT and be hoping you're 3barrelling as usual. In that case I don't think he will bet the river, since he has decent showdown value. If you check and he bets then either he has played his draw deceptively passively, or he has been calling you with what he thinks is the weaker hand but with the intention of moving you off it on the river. But does he really expect you to fold, say, AA in that spot? I'm guessing no, so if he bets out he either has you beat or was calling with virtually nothing with the sole intention of moving you off your hand on the river.

Conclusion: I think that the standard "check to induce bluff" may not be optimal here, since if he bets he's more likely to have a hand than to be bluffing in this particular spot.
Check-fold seems better, unless you have a read that he's capable of calling with air twice only to steal on the river or that he's capable of extremely thin value bets. In case of a more passive opponent, I would advocate the same line but for different reasons: he's more likely to actually have the flush and less likely to bluff since he's passive.

Hmm given Xast's image (I assume he is the sort of player who will fire on all 3 streets) I could see a set of 7's flat calling turn - and of course he also might have hit with 5's on the river - set is the least likely though - I was listing them in descending order of likelihood...

I think if you check you have to call anything up to about a pot-sized bet as repping the flush in position is such a no-brainer- but a blocking bet is going to induce the bluff raise repping the flush from any player who smells weakness.

If villain has hit the flush he will view your check as 'shutting down' and so may bet out a relatively small amount as a value bet.

I hate the river too but think check call is best here unless you have a note that villain never bluffs or something

I doubt that a good player would play flush draw so passively in position. Assuming that he is not good and not so aggro (aggresive player would raise on flop or turn) I like a block/value bet of about 120. Fold to a raise obviously.

Edit: Didn't notice that Droqqa posted, I agree.

CR AI and open shoving are both horrible.
Open fold >open shove.