It depends how you camp. I have four T105 CG batteries, 2000W inverter. But I NEVER use my RV without being connected.
I am going to replace them soon and I have pretty much talked myself into replacing them with two Group 27 dual purpose, sealed batteries.
Why? They are the same size, 31s wont fit, I converted all my lights to LED and I hardly ever use the inverter, maybe for tv and its LED, too.
I leave it plugged in all the time.
I have a watering system but I forget to add water every month and keep letting the electrolyte level go down.