It's not so much the chassis that might cause windshield problems - it's the design of the coach front cap where the windshield is seated. Spartan & Freightliner both build a chassis with excellent strength & rigidity, but the motorhome body builders are too often sub-par.
Of my three motorhomes, only one of them (a 1996 35 footer) was prone to separating the windshield and I had to be cautious bout how I jacked it up when leveling. Roads were never a problem. The other two, a 2002 and a 2004, never caused a problem.
Former owner of 2004 American Tradition and several other RVs
Home is in the Ocala Nat'l Forest near Ocala, FL
Summers in Black Mountain, NC