Its a hand that can be played many ways, preflop and on the flop. Only one real mistake I see. You should have bet the turn, probably all in. He's real unlikely to be slowplaying anything here, with the big pot size and the flush draw possibility. I'd either put him on a low ace (scared you have him out kicked), a high pocket pair (which fits the preflop action and check on the flop), or a flush draw, each of which you beat, but all of which could beat you on the river. The check on the turn is serious weakness, in this case. Go all in and hope for a "pot commited" call, since you almost certainly have the best of it.

I personally probably would've played the flop the same way, and sometimes preflop the same way. I'd be worried he had me beat until the check on the turn.