Hers’s my .02…and that may be all it is worth. Check your owner’s manual for what GM considers and acceptable replacement battery. AGM, flooded acid…etc, all operate differently. Care and maintenance is different. Your truck may not be truly compatible with the AGM – especially if the camper backfeed/charges when you are hooked up and plugged together. In other words, your inverter might charge at a rate destructive to the non-OE style battery.
My personal experience on GM batteries is I get between 4 to 5 years out of them – like clockwork. You don’t have to get a Delco battery – but make sure what you get is not only the right size and amp hour…but the correct TYPE.
I put a Optima blue top in my boat this last year. I have the boat in storage mode. I was charging that battery with a “Battery Tender” brand – but just learned that could destroy the battery. I bought an $80 Optima brand charger that has a specific setting for their batteries for charge and storage. It makes a difference.