There's a thread about a warranty not being honored because of "abuse" on the other forum.
It's been stated that ANY charger left on an AGM battery will eventually cook it.
My only personal experience with AGM batteries is on my 06 Liberty CRD.
Liberty CRD's (diesels) came from the factory with an Optima Red Top AGM that failed early. I replaced it with a Sears P1 AGM 6 years ago after two Red Tops.
I noticed a big difference between the two, the full charge voltage on the Optima is several tenths lower and the P1 is the same as a wet cell battery.
I think the low maintenance of an AGM is more precise then people believe.