River action vs Steve Giufre

[PokerMike]

Would appreciate responses from people that have played against Steve.

Party Poker 100/200 Hold'em (5 handed) FTR converter on zerodivide.cx

Preflop: Hero is Button with 7[img]/images/graemlins/spade.gif[/img], J[img]/images/graemlins/club.gif[/img].
<font color="#666666">2 folds</font>, <font color="#CC3333">Hero raises</font>, <font color="#666666">1 fold</font>, Steve Giufre calls.

Flop: (4.50 SB) 8[img]/images/graemlins/heart.gif[/img], 5[img]/images/graemlins/diamond.gif[/img], 7[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
Steve Giufre checks, <font color="#CC3333">Hero bets</font>, <font color="#CC3333">Steve Giufre raises</font>, Hero calls.

Turn: (4.25 BB) 3[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Steve Giufre bets</font>, Hero calls.

River: (6.25 BB) K[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
Steve Giufre checks, Hero...?

Is this a valuebet? I was kinda worried about my kicker, among other things.