I'll give it my quick two cents while procrastinating at work - I agree it's a really tough call but my instinct is to fold this. I don't think he leads the flop with many diamond draws (like do you think would he lead out KQd, QJd, JTd here? I don't think so), so I think he calls the turn checkraise with roughly the following (and folds out a lot of his high broadways and non spades):
*Sets - his range is heavier here than ours is
*Stronger aces, maybe flush draw aces with a low kicker
*Lots of straight draws
*Spade draws with a pair

So I view the river bet as he would prefer for it to not to check through. He knows you could have been raising for value as well with a combo spade / diamond draw or pair, so it's hard for me to imagine he calls the checkraise and then bluffs at it.

Criticism of my analysis appreciated!

I think the river has to be a fold. I don't think he can really bluff with anything on this river unless he has specifically Asx. I don't think he necessarily is going to make that play. Definitely not at a high frequency and even less likely with a less than half pot sizing.

My first post to this site . For what's its worth I agree with previous comments. Very few bluffs in his range . Only poss bluffs is something like KJd/KTd on the times he barrels these. Has some showdown value hands that you beat on the river like AK/AJ , but very unlikely he would lead the river with these hands. Even with a set I think he would not just call the raise on the turn then lead the river. I think almost always this is a flush. Easy fold IMO.

The Qs one of the worst cards that could come on the river for you. So just as a note if he checks the riv. IMO you should check behind as I don't think you can bet for value.

Also because villain can have very few bluffs in his range IMO it is a bad bet by him. He should either bet small or check.

I agree with you all people, I ended up folding :)

Fold

Not sure I like the raise OTT. First, it's too large imo and 2nd it's a pretty gross spot if you face a re-raise. I don't think I'd want to have much of a turn-raising range here against a reg in general. And I also think that calling is higher EV than raising OTT.
Maybe raising 99 and JTs or 76s to balance with bluffs is good but I really don't love going nuts with that crappy two pair here. We are deep and villain definitely has range advantage. Overall his line looks pretty nutted by the turn betting oop and and considering his sizing.
It's almost impossible for him to have a bluff when he donks the river.

As played I'd call OTR with 99, 88, JdTd, 7s6s, and raise AsXs, JsTs combos. Everything else is just a fold in my opinion.