Checking flop isnt awful. I'd say you should be betting it here about 70% of time, which means we are checking it through just under 1 in 3 times.
I hate polarized hands like this. His turn C/R is essentially a pot sized bet and that means he's either betting a combo draw or puts you on a big hand and wants to get max value from his set.
OTR, he bets 5/6 pot. This could absolutely be air sometimes, but also could be a set of 7s. It's gross that we have blockers for a set of 9's or Aces.
I can't see him getting so aggressive with a worse 2pair hand. This is 77, AQ, 99 , or Air. Is villain really tricky enough to turn his Ah7h into a bluff? doubtful.
I'm leaning toward a call, but I guess that's because I suck and get owned postflop. There's just so many draws that missed here.
....but villian knows this! ugh!!!