You should be using a smart charger for any AGM battery. The old fashioned chargers will cook an AGM. I know, I have done it.
I went this direction as a fairly in-expensive option: http://batteryminders.com/details.php?prod=12248
Works for Flooded/GEL/AGM with multiple amperage options as well as trickle charge. I've been happy with it so far. There was a pretty good write up on it in 4x4 Toyota owner a while back that influenced my buying decision.
But I'm done with Optima personally. Just based on location of assembly. I try to buy USA products when ever possible, well except for my actual truck
. For the record my US made Optima was a great battery.