Tires, axles 7 or 8 k, frame build, construction, deck, roof, wraps, all so important when considering what brand to look at. You want something that will hold up against the pounding and living.
Units we have been impressed with that meet our criteria are: Excel, DRV, Trilogy (although they are so new, I doubt you will find used ones) King of the Road
we just bought an 06. There is lots of talk on this board to read on selecting a quality unit and testimony/recommendation that I am sure can be useful to you.
06 King of the Road 37RLQS
06 Coachman Cross Country 5.9L 300HP 382 DS
03 Jeep Wrangler, 4.0L James, Trina, SMSgt, USAF Ret