Capacity is king. No need for superfast AGM charging with solar. IMO 80% down on an AGM is harder on the battery than 50% on the wet cell. Either can go down 60% or 70% for part time use without too much worry.
Only if you can reposition the AGM to get the capacity up... but the extra battery(s) will increase cost.
AGM batteries have a lot of advantages. Many of them irrelevant to the RV world. They don't out gas but RV's typically have vented battery compartments.
They can take a much higher charge current but most RV's have kind of weak chargers.
They can survive more physical vibration like an off road vehicle or machinery would subject them to, but RV's typically don't go extreme off roading.
They don't require checking the water levels but that's really quick and easy.
I am looking at putting an AGM in, along with replacing the converter with an inverter/charger, then a 290 watt solar on the roof. I figure running the generator for about an hour in the AM while the kids abuse the shower (hairdrier) should put back most of what came out of the battery overnight + breakfast. The solar can do the rest during the day.