Trap or Bet?

[Thriller]

Moderate steal attempt shortly after the break. New to the table, only 1 orbit so far.

PokerStars No-Limit Hold'em Tourney, Big Blind is t150 (9 handed) converter

Button (t11250)
SB (t9365)
BB (t5500)
UTG (t4680)
UTG+1 (t7155)
MP1 (t4080)
MP2 (t4700)
MP3 (t8450)
Hero (t4240)

Preflop: Hero is CO with K[img]/images/graemlins/club.gif[/img], J[img]/images/graemlins/club.gif[/img].
UTG calls t150, <font color="#666666">2 folds</font>, MP2 calls t150, <font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises to t750</font>, <font color="#666666">3 folds</font>, UTG folds, MP2 calls t600.

Flop: (t1875) J[img]/images/graemlins/diamond.gif[/img], Q[img]/images/graemlins/heart.gif[/img], J[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
MP2 checks, Hero checks.

[So I'm wondering the optimal way to play this. Did I do right by checking, or should I have fired away on the flop?