I switched to two 6V AGM batteries (from two 6V flooded cell). My batteries are under the floor and DIFFICULT to monitor so I am glad to eliminate that need. Also, I dry camp often and they absolutely do have long life. For those and other reasons I think that they are worth the cost.
HOWEVER, apparently many chargers through the converter are unable to charge the AGM's to their full potential. I am still researching this but, it looks like I will have to add a different charger capable of shoving that extra power that AGMs have, into them.
Also, your alternator may (or may not) be up to the task. A long drive will fully charge my AGMs but it takes a while. There are things you can do to boost the output of the alternator to get a full charge quicker but again, I am still researching that.
Bottom line ... to get your money's worth out of AGMs, research whether you might need a more powerful charger for the more powerful AGM batteries and, whether your alternator output is up to the task.
I welcome an education on this and will pass on what I learn as I proceed.
