Latest battery tests from CR. Interesting to see that AGM (glass-mat) batteries generally did better than traditional ones. But at twice the price, they don't last twice as long... so if you don't mind changing the battery more often, seems to make financial sense to stay with the 'old type'.
This test does not cover our Group 86 batteries. But it does cover Group 75 size at the end of p3, which are the same size, just different terminal placement (and many places sell 75/86 batteries with two sets of terminals). For the price/performance tradeoff, it looks like the Bosch batteries from PepBoys might be good. YMMV!
Enjoy.