I lead out with a bet of $150. Kills pot odds for the straight, but if player has hit the straight, you'll know and can let go. If the villian has an OESD, you don't want them getting another card for free.

If you check, let's say, and a 3 comes, your decision is still just as hard as the last betting round, as he could be trapping you. With no reads on the first hand, this play is risky. You have a monster, but it may not be the nuts.

Sidenote: I'd like to predict we'll see some sort of straight flush draw in this hand.