For the 2/5:
When you check the turn AKd, AQd, will usually be betting. The weird thing is those hands should probably be continuing on the flop. As would pocket TT, pocket 99, and any screwball hands like a frisky QJd.
My only real concern on that river is actually a rivered set of 6s. That's the only thing I can see played that way, and quite frankly his bet sizing is way small for that - especially considering his gungho bet pre-flop.
Factor in that AA, KK would not have 3-bet pre-flop THAT much. $120 would be the number for that I'd think. $150 looks more like JJ, AK, AQ - the "I'm ok with a call but would prefer a fold" sizing.
Add it all up and it's a call.