OK I am REALLY trying not be results orientated.
The situation:
50 odd left. Average stack is 50k. I have 85k at start of hand and villan is the only player at the table who has me covered. Blinds are 600/1200/100.
Villan is a bit of a donkey not to put too fine a point on it. He called an all with 10 8 for half his stack cos it's his fave hand. Then called an all with J 10 for 15k blind 400/800 (quarter of his stack) and won. He plays a wide range of hands and obviously over values them
My image: I've been fairly active and value bit pretty thiin on the river a couple of times. I bet half pot on an 87642 board with A8 (which was good and got a caller) and have recently been bluffed off a pot with 4 6 after value betting on the river perhaps too thin! I've also value shoved the river with AQ on a 642Q7 board and got a call from QJ. I've also been opening my fair share of pots.
It folds round to me on the button and I look down at KK. I raise to 3475 and find the villan calling from the big blind. I can't begin to put him on a hand cos I know he's calling with a very wide range.
The flop comes down J 10 2 two spades. He checks I bet 6500- he calls.
The turn is a 4 (still 2 spades). He checks again so I bet 18k- one to bet for value against a Jack, 2- out price him from a draw. He tanks for a bit before calling. I'm a little worried that he may have J 10 but not overly. I'm also pretty sure now he doens't have spades.
The river comes another 4 and he knuckles it one last time. There's around 58k in the pot now. We both have 57k left. My question is:
Should I value bet? Should I value shove or should I just check it here?

There is a lot of money in the pot- and if I win I'm up to 114k. If I value bet or even value shove I'm up to 161k.
Obviously if i check and lose I still have a healthy 57k with blinds just about to go to 800/1600/100. If I bet and lose I'm obviously out.
Is it sometimes to leave some value on the table to preserve your tournament life???