Welcome to IRV2. Hope you have a lot to share while you enjoy your RVing experiences.
Any engine is reliable if the proper maintenance was performed on regular schedules. The coach is the same thing as far as maintenance and TLC were performed.
A lot of original manufacturers (OM) were bought out during the great recession of 2007 so some parts diagrams and blueprints were lost in the shuffle to the new owner. However, most OM engineers used standard parts that other OM engineers used so things like refrig, air conditioners, stoves, showers, etc., are pretty standard. That is until you get into the really expensive coaches like Newmar, Rexhall,American Coach, just to name a few use top end appliances and real wood trim.
So if you find a coach that was properly maintained with regular maintenance done and you trust the owner to tell the truth, and he has all the maintenance records then the coach ought to be something to consider.
There are always gremlins cropping up in any coach the question is how big are the gremlins.
Retired Army, Disabled Veteran
Wife, me, and 2006 Coachman Cross Country 372DS makes three, Demco Kar Kaddy SS