[sputum]

PF - easy call closing the action with a chance to put players in the middle when you hit your set, no worries there.
Flop - I always lead here, the pfr is oop with two behind on a monotone flop. (EDIT: so a cbet may not look attractive to him) Don't mind the check so much on less drawy boards and in practice I stack off to a flush with a set quite a lot because it's difficult to tell the difference between a made flush and a big draw.
That's not to say the original flop check was a huge error or anything, I just think leading out gains some value over time. But once UTG+1 bets I think you HAVE to raise unless you can put him on a flush/higher set with some certainty (unlikely)
You are pretty deep so some caution is called for but UTG+1 did you a huge favour. Take advantage of it.
Turn is tricky as played. Could be anything - AA Ax KK JJ (I've seen it before [img]/images/graemlins/laugh.gif[/img]) given the uncertainty and effective stacks I quite like your fold but the hand has kind of meandered to this point and you pretty much gave him a free card that probably helped him (whether to top set or one/two pair we don't know)
At the table if I got to this stage I'd prob push hoping for AdKx (or something that gives me a shot at least) then stab myself in the leg with a fork when I saw he hit a two-outer for a near-600bb pot and it only cost him 7bb to see the turn. The flop check-call leans me toward AdKx a little but not enough to be really confident.
Monotone flops used to freeze me with low sets but betting them on the flop at some point is the best way to play them imo. And the bet is usually for value. Bottom set is good here a huge percentage of the time.
EDIT: I used to cringe and fold a lot in this type of situation (where I thought I'd misplayed an earlier street, it still happens quite a lot [img]/images/graemlins/blush.gif[/img] ) but the push is win-win in that you take his cash or relearn a lesson (if you agree with me, anyway)
The table is pretty deep and I don't play 300bb stacks much so I could be wrong of course [img]/images/graemlins/tongue.gif[/img]