There are situations where AGM is worth spending twice as much compared to flooded lead-acid.

• the ‘dweller installs the battery bank in a location where it is not reachable for normal maintenance
• the ‘dweller needs to mount the battery on its side for some esoteric reason (or is 4×4 trekking so the RV itself can end up in weird angles)
• the 'dweller is a heavy off-roader and needs the internal plate support AGM provides in violent shaking and vibration
• the ‘dweller wants to run heavier-than-normal loads relative to bank size (microwaves, electric coffeemakers, electric cooktops, etc). Note this means the battery can be drained faster, not that it provides more capacity. Overall charging will take roughly the same amount of time.
• the ‘dweller has has an actual (not imagined) chemical hypersensitivity
• the advanced ‘dweller is running a single battery for both house and starter systems (“shallow cycling”) <– not for beginners!
• the 'dweller is intentionally running the bank in PSOC and wants to get through Bulk charging as quickly as possible due to limited charging opportunities.

Lithium does things as well or better for lower overall cost-per-kHw, but still costs more upfront.