We bought what was a mid-high end coach when it was built (in 1996) and took a year to whip it into shape. We set out on a 6 month, 16 state and 6000 mile trip last winter and we had zero mechanicals. I had some roof work to do, and I replaced most of the working parts in the toilet, but everything else continued to work throughout the trip.
OTOH, I ran into a guy in Shreveport that was trying to get his brand new Tiffin back to California. He had already driven back once to Red Bay from Arkansas and was on his way back again, this yime from Oklahoma. He'd take it back to the factory and fly home, then fly back to pick it up.
Here's the deal. If you're in the least bit mechanical, you can fix mot stuff that will break in an older rig once you understand how stuff works. Doing so on the road in a new bus will likely void the warrantee.