Originally Posted by ike
Big river sizing seems fine to me. You're not really looking to vb river super thin (or if you are, maybe you can have a smallbet range and a bigbet range).
In an 8game mix having balanced / unexploitable strategy seems irrelevant to me. You're certainly not going to be playing enough NLHE hands with AB that it's going to matter and you should certainly just be trying to maximize EV on this one hand.
With that said i definitely think you are going to get more river value with a smaller bet size and might actually induce some tight laydowns with the larger bet size. I think you will get many more hero calls by making a more reasonable bet. If you are going to bluff the river here i think the larger bet size has more merit since having a balanced range doesn't matter.
As played, i don't think AB is ever bluffing and you can safely fold (easier said than done getting that price)