ATo after 3 limpers

[vipchump]

PokerStars No-Limit Hold'em Tourney, Big Blind is t400 (9 handed) converter

I'm not sure I like river play here. Check behind?
Big stack has been limping almost every hand and will bet with piece of the board. Has only shown down big hands though.

Flop play was iffy too? Like the call?

CO (t6405)
Hero (t8778)
SB (t8697)
BB (t20075)
UTG (t26055)
UTG+1 (t35985)
MP1 (t7770)
MP2 (t4505)
MP3 (t11624)

Preflop: Hero is Button with A[img]/images/graemlins/spade.gif[/img], T[img]/images/graemlins/club.gif[/img].
<font color="#666666">1 fold</font>, UTG+1 calls t400, MP1 calls t400, <font color="#666666">2 folds</font>, CO calls t400, Hero calls t400, <font color="#666666">1 fold</font>, BB checks.

Flop: (t2200) J[img]/images/graemlins/club.gif[/img], Q[img]/images/graemlins/heart.gif[/img], K[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(5 players)</font>
BB checks, <font color="#CC3333">UTG+1 bets t800</font>, MP1 folds, CO folds, Hero calls t800, BB folds.

Turn: (t3800) K[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">UTG+1 bets t1200</font>, Hero calls t1200.

River: (t6200) 3[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
UTG+1 checks, <font color="#CC3333">Hero bets t6353 (All-In)</font>, UTG+1 folds.

Final Pot: t12553