Effective stacks 450. Villian is a solid TAG. He can get somewhat LAGgy at times. I've played with him a lot and he's definitely capable of making moves.

I raise 99 to 25 from MP and Villian calls out of the BB.

Flop ($50): 10 10 4 r

Villian checks, I bet 40, Villian calls.

Turn ($130): 10 10 4 (8)
Villian leads for $125...

The stop'n'go confused me. Why not just c/r the flop? Here's my thinking: I almost always c-bet heads-up. Villian knows this and probably has me on whiffed overs, not a PP. Once a low card showed up on the turn he thought the pot was his for the taking. Am I overthinking this? I'm almost certain he 3-bets a bigger PP pre-flop, so this looks like either a ten or air to me. Anyway, I called.

River: ($380): 10 10 4 8 (4)
Villians leads for 200, I only have 250 left. Am I committed here? I hated this spot. I guess my decision point was the turn, but once I call, how often does Villian fire another barrel in this spot? Thoughts on turn and river appreciated.

Once you call on the turn villain must realize that you're pretty much committed to the hand. Only the very bottom of your range will fold to a 1/2 psb on the river. You're not folding QQ+, maybe not JJ. Then again, if you're pretty confident he 3bets pre with a bigger pair then there isn't much he can take this line with. He's either got a T, 88, or air. Betsizing makes this look kind of bluffy though...his psb on the turn isn't the sort of bet thats going to get called often.

I guess it depends on how often he shows up with air here since your hand is obv a bluff catcher at this point. You said he's capable of making moves, so maybe this isn't the worst spot for a call. That said, I'm gradually turning into a calling station (this was instafold for me not so long ago) so take that into consideration when judging my feedback.

I use the stop and go move quite frequently on boards like this and almost always as a bluff. I honestly don't mind your turn call all that much but, if you think he's bluffing, why not just push? How would you have responded if an overcard rivered and he bet?

I guess what I'm saying is that you have to decide on the turn how committed you are to playing this hand. Is he the type to try a bluff then shut down on the river if he thinks you're committed? If you don't feel comfortable playing it for your stack then I wouldn't call his turn bet--especially if you think he'll fire most rivers.