Rubber roofs by themselves are decent, but the implementation on RVs essentially stamps an expiration date on the rig, especially if the rig is fiberglass and prone to delamination.
It doesn't cost that much more, why don't RV makers go with an aluminum roof like Livin' Lite does? If placed and bent around the corners, other than around vents and skylights, there is no place for water to get in even if all the caulk seals failed. To boot, a branch scrape that goes undetected would not create a major leak and total the rig.
The ideal would be a one piece metal roof combined with the rvroof.com sealant on top. No caulk, no Eternabond, multiple layers protecting against water, and top tier insulation.