NL25 - KK stack sizes

[reemas]

I thought this was a tricky spot. I have kings and an A hits the flop. I'm first to act and I lead out. Opponent takes a long time and shoves.

The tricky part is c-betting leaves me close to pot committed (based on my opponents smaller stack size), and checking does me no good. So should I shove instead? I find myself in this spot often given my opponents stack sizes.

Opponent is 21/15/2.5 after 30 hands (don't know if this was accurate during the hand, as PT only shows final known stats).

Poker Stars, $0.10/$0.25 NL Hold'em Cash Game, 6 Players
LeggoPoker.com - Hand History Converter

UTG: $8.95
MP: $9.65
CO: $21.20
BTN: $20
SB: $33.10
Hero (BB): $37.90

Pre-Flop: K[img]/images/graemlins/spade.gif[/img] K[img]/images/graemlins/heart.gif[/img] dealt to Hero (BB)
UTG calls $0.25, MP folds, <font color="red">CO raises to $1.25</font>, 2 folds, <font color="red">Hero raises to $4</font>, UTG folds, CO calls $2.75

Flop: ($8.35) 5[img]/images/graemlins/heart.gif[/img] 4[img]/images/graemlins/spade.gif[/img] A[img]/images/graemlins/heart.gif[/img] (2 Players)
<font color="red">Hero bets $6.50</font>, <font color="red">CO raises to $17.20 and is All-In</font>, Hero ?