flop check

[James.]

i post in the CO at a 6handed table. it was a good game with some known(to me) fish and LAGs.

UTG is standard 6max LAG(45/7/3.2) but he is less aggro preflop, but very often gets out of line postflop. he bets draws, any pair, and nothing(i.e. is very capable of bluffing).

bb is fish(60/3/.5). sb is unknown.

UTG limps, folds to me with A [img]/images/graemlins/club.gif[/img]7 [img]/images/graemlins/club.gif[/img] and i raise my post, fold to UTG who calls.

Flop(5.5sb): K [img]/images/graemlins/spade.gif[/img]8 [img]/images/graemlins/club.gif[/img]7 [img]/images/graemlins/heart.gif[/img]

he checks, i check it back.

Turn(2.75bb): 4 [img]/images/graemlins/spade.gif[/img]

he bets, i call.

River(4.75bb): J [img]/images/graemlins/heart.gif[/img]

he bets, i call.

try to put UTG on a hand or range of hands.

what line would you take in this hand? why is it better?