Is this a clear value bet?

[cmwck]

Villain is playing over 55% of his hands, and is unremarkable otherwise.

PokerStars Hold'em (4 handed) converter

Preflop: Hero is UTG with Q[img]/images/graemlins/club.gif[/img], K[img]/images/graemlins/spade.gif[/img].
<font color="#CC3333">Hero raises</font>, Button calls, <font color="#666666">2 folds</font>.

Flop: (5.50 SB) A[img]/images/graemlins/club.gif[/img], Q[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets</font>, Button calls.

Turn: (3.75 BB) 5[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets</font>, Button calls.

River: (5.75 BB) 5[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
Hero ...?

Who definitely bets the river?