Line check - hand 2

[Isura]

Villain is unknown. Fire again on the turn or take the free card? What are the pros/cons of each? I meant to raise $3 preflop. Thanks guys.

Party Poker No-Limit Hold'em, $ BB (6 max, 5 handed) FTR converter on zerodivide.cx

SB ($65.80)
BB ($36.40)
UTG ($42.05)
Hero ($97.80)
Button ($94.05)

Preflop: Hero is MP with A[img]/images/graemlins/club.gif[/img], K[img]/images/graemlins/club.gif[/img]. SB posts a blind of $0.25.
UTG calls $0.50, <font color="#CC3333">Hero raises to $2</font>, <font color="#666666">3 folds</font>, UTG calls $1.50.

Flop: ($4.75) 2[img]/images/graemlins/club.gif[/img], 5[img]/images/graemlins/club.gif[/img], 6[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
UTG checks, <font color="#CC3333">Hero bets $4</font>, UTG calls $4.

Turn: ($12.75) 2[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
UTG checks, Hero ??