Bottom line. Any motorhome can have problems. However, when a manufacturer keeps building motorhomes with the same problems and no fix, that's serious. Tiffin has done that.
We had excellent workmanship on our Newmar...absolutely no complaints. That's why we bought one. We talked to many satisfied owners in campgrounds before purchasing it.
One thing about Newmar...all levels are built on the same production line so they all receive the same workmanship. Not all components are the same but the worker care is the same. Even with this, there can be problems. Builds are not perfect and components/chassis, etc. do fail. It's not always the manufacturer's fault. Many outside companies supply various parts.