[Harv72b]

If your opponent is unknown to you, you are most likely unknown to him. And as was already mentioned, unknown micro players (especially the type that open limp) aren't exactly world reknowned for their ability to fold postflop.

This hand is a bit of an exception, though, because we did at least flop a draw to a very strong hand. As you mentioned, depending on villain's hand when he does call, we could very well be looking at 10 outs twice, which makes us just a little worse than a coin flip assuming we're going to the river. Make his hand an underpair to our 8 & we actually have a bit more equity as we can win with running Q9. So anyway, yeah, I will often bet out with a hand like this (as well as when I believe I have the best hand, even if that "best hand" is something like 32 or ace high). As you sort of alluded to, the equity of our draw plus our (limited) folding equity turns this into a +EV play.

Incidentally, I don't think check/call is always a bad play here, as we're often going to be given a free card on the turn when our opponent is betting with air, and may also be able to steal the pot with a river (or even turn) lead when we miss. But I would not assume that any of those moves would work often enough against an unknown micro opponent.