I made the move to a pair of 6v cart batteries 5 or 6 seasons ago...still working great.
we also have a honda eu2000 as we do a lot of off-grid camping in our 25ft TT.
I seldom put much of a load on batteries anyway...typically lights , water pump, heater blower in season or small rotary fans (cig lighter models) in summer...and we are seldom off grid for more than 3 days...on occassion, I'll run an inverter tapped off the fuse panel..it powers our flat panel 28" TV nicely if we're parking lot at a truck stop, walmart kinda thing for a bit.
but when we're out in the middle of nowhere i just crank the honda..which of course is charging the batteries too.