Speculative hand from Stars 10+1 Deepstack

[Rasputin]

PokerStars No-Limit Hold'em Tourney, Big Blind is t2000 (9 handed) FTR converter on zerodivide.cx

Hero (t115948)
MP1 (t90781)
MP2 (t255421)
MP3 (t86089)
CO (t47965)
Button (t42818)
SB (t62386)
BB (t62542)
UTG (t89469)

Preflop: Hero is UTG+1 with 6[img]/images/graemlins/spade.gif[/img], 5[img]/images/graemlins/spade.gif[/img].
<font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises to t6000</font>, <font color="#666666">1 fold</font>, MP2 calls t6000, <font color="#666666">5 folds</font>.

Flop: (t12800) 8[img]/images/graemlins/spade.gif[/img], 4[img]/images/graemlins/heart.gif[/img], 3[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">MP2 bets t6000</font>, Hero calls t6000.

Turn: (t24800) J[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">MP2 bets t8000</font>, Hero calls t8000.

River: (t40800) 5[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, MP2 checks.

Final Pot: t40800

My plan had been to follow up with preflop raise with a nice half or two thirds pot bet unless the flop came too scary.

Problem was, the guy who called was the only guy at the table who could bust me and who had shown himself to be competent and aggressive. When I saw it was me and him I ratcheted down the aggression several notches to keep the pot small. We were well into it but still shy of the money and I had a healthy enough stack to make a run.

So should I have been more aggressive here, or was being more cautious appropriate?