[Heisenb3rg]

I don't agree fully with above, you don't gain the same info. You gain the info that he can screwplay the turn with a weak hand in 3 way pots and give up the river.

You don't get to find to out info on his PF capping range. IMO a fairly important peice of information. He could have done this on the turn with JJ for all we know. When nearly all players cap, my instinct is to get passive with some fairly strong hands. If they are capping light, im missing value. If I know they can cap light, I can become more agressive, extracting proper value.

But I don't agree with kwaz. The more I think about the river situation (I like way the way ILP put it) it's probabily not very marginal a river bet at all and there's good value in it.
It's not even close to sacrifice this value for information that COULD gain a little more value in a future situation.

The great thing about LAG's is they play so many hands that you get to observe them frequently, therefore sacrifing immediate value for information about their odd tendencies is less valuable than it would be against a tighter player.