OK villian is seems somewhat loose. I do no have exact stats but after about 40 hands he had a 4.0 turn aggression and inf river aggro. He hit the pot button very quickly if that means anything.

Full Tilt Poker, $0.25/$0.50 NL Hold'em Cash Game, 5 Players
LeggoPoker.com - Hand History Converter

Hero (SB): $50.60
BB: $49.50
UTG: $65.30
CO: $52.25
BTN: $80.65

Pre-Flop: A J dealt to Hero (SB)
2 folds, BTN calls $0.50, Hero raises to $2, BB folds, BTN calls $1.50

Flop: ($4.50) 3 5 J (2 Players)
Hero bets $3.20, BTN calls $3.20

Turn: ($10.90) T (2 Players)
Hero bets $8, BTN calls $8

River: ($26.90) 3 (2 Players)
Hero checks, BTN bets $26.90, Hero

well, this is a great play but since your asking should you call then the answer is YES

i love the river check to induce a bluff here and i don't think thats why you did it, i think you got scared and now letting him try and take the pot away from you

Block bet on river is bad vs this type of opponent? I probably would bet on river about 10$...

what are you blocking???

a 3 has you beat and that is the only thing im worried about and its like a 5% worry out of 100

IMHO, he has no overpair or he'd have reraised preflop. I don't think he could call those flop and turn bets with 3X. Not even flush or str8 is possible so... with that call from the button, I put him on a [A-T]J, Jxs... Anyway, you seem to be ahead.

I don't think he can call a raise preflop with 46, 23 (A2 would be sick).

He's very aggr, so if you're not "sure" you're ahead, don't let him take the pot from you in the last bet. You have to bet and big so he understand he can't bluff at you (unless, as sb said above, you bet to induce a bluff).

All that I said is now, after the hand, but without so much time to think, maybe I would get froghtned with that river bet...

Aren't instabets like this always bluffs?

I would probably call if he did instabet. If he tanked and bet, it would be close and I would probably fold.

instacall, 3 is a good card for you