standard overs situation
 

Villian is not a maniac, and my image isn't too crazy either. Is a turn peel ever in order? I think that usually this is a pure 4 outs, sometimes it is 7, and its almost never 10.

PokerStars 10/20 Hold'em (6 handed) Poker Stars Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

Preflop: Hero is Button with Q[img]/images/graemlins/diamond.gif[/img], K[img]/images/graemlins/heart.gif[/img].
<font color="#666666">1 fold</font>, <font color="#CC3333">MP raises</font>, <font color="#666666">1 fold</font>, <font color="#CC3333">Hero 3-bets</font>, <font color="#666666">2 folds</font>, <font color="#CC3333">MP caps</font>, Hero calls.

Flop: (9.50 SB) 3[img]/images/graemlins/spade.gif[/img], T[img]/images/graemlins/club.gif[/img], 9[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">MP bets</font>, Hero calls.

Turn: (5.75 BB) 2[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">MP bets</font>, Hero folds.

Final Pot: 5.75 BB

Re: standard overs situation
 

You're getting 6.75 to one, which means you need to have a little less than 7 outs on average. But you will get at least one bet on the river if you make the best hand, and sometimes two or more when it's a Jack usually. I like to peel here since it's pretty close, and it encourages people to fire the turn with weaker holdings in the future, which should be good for you in these situations.

Re: standard overs situation
 

Its close and depends on his capping range. His range is probably fairly tight here from UTG+1. I agree with ggb that for meta it is better to call turn, but i don't think you have quite enough outs.
Basically the river has 3 possibilities.
You hit J and win more than 1 bet on average.
You hit Q/K and probably come out pretty close to even EV.
You miss and fold.
In reality I think we should look at these situations like we have 4 outs since we don't know if a K or a Q are good and will be calling on both. So we have 4 outs to the str8, 6 outs to a pair we don't know is good, and 36 cards we fold on.

I think if capper is the button or CO than you can probably peel since your pair outs are good more often.

I think your pair outs being good more often is more important than winning more bets on a J vs over pairs.
I'm too lazy to stove his range vs yours here, but thats basically what it comes down to.