Villain is 31/23 and opens 15% over a decent sample. Cbet is 45% and he delayed Cbets IP 48%

He probably has some better hands in his checkback range. Not really sure whether this means AQ would be a call or a fold...

I was thinking he can check back with his PPs, AK and other A-high hands, some Kx hands and some trashy hands that don't cbet. When he bets the turn I don't expect him to suddenly come alive with AK or his PPs (why would he?), so I called the turn hoping he would check back river. If the river wasn't so terrible I would have called.

In this particular hand on the river I really felt like donking out about $1.20 (or maybe even overbetting?) to fold some weirdly-played Jx or AK or something, or even to stop him from bluffing with anything. But I think his range contains too many straights for checking back the flop so just give up.