Having owned several used motor homes, and reading this forum. It appears new motor homes have as many problems as used.I think the used ones have the bugs worked out.
I've had two used motorhomes. The first one was a money pit. Paid 12k for it, spent 12k over the next four years fixing it and sold it in good condition for 12k.
The one I currently own was well maintained when I bought it and it has been virtually trouble free (KNOCK ON WOOD) for the last eight years and 72k miles.. Luck of the draw.