In the boating industry there are two iron clad maxims: Nothing is either waterproof or maintenance free. AGM's offer many advantages but some of them are of little or no value relative to the significantly higher cost. As noted they are not maintenance free. Do you really need to mount them on their sides or upside down? I seriously doubt it. Do you have a smart charger that has a setting specifically for AGM's?
The point being that not everyone needs AGM's, they are wonderful batteries but come with a very hefty price tag compared to a quality deep cycle wet cell. The way most folks use their RV's, with the exception of full timers, a set of wet cell Trojans (6 or 12 volt properly installed), will give you more amps per buck than an AGM. :C
