A few AGM advantages:
AGM is the winner for unattended winter storage, indoors or out. The lower self discharge rate is the reason. AGM can freeze if the self-discharge rate during storage drops the voltage too low, but only needs to be thawed to recharge. Unattended wetties can also freeze, however, are ruined due to case swelling and plate distortion.
No cleanup of chalky/corroded battery terminals.
No periodic replacement/cleaning of corroded battery tray.
Can lay on side without spilling acid. Great for squeezing them into places a wettie cannot go.
No distilled water.
No wool clothes.
No watering system.
Pound for pound, No worry about low-voltage-disconnect when running the inverter.
A lie can circle the world.....
before the truth leaves the starting gate. :)
HTH;
John