Mimi Maness, Dutchmen before 2006 are well built, before the company was sold. They also build Komfort, which is well loved.
Any older models, of course, will need to be leak-proofed (roof maintenance), and possibly gutted and repaired (depending on water damage).
Also, RV fridges, water pumps, and hot water heaters are among the first to need replaced. You’re lucky if they last five years.
Jon