I'm not completely with bumpy but do agree that the roof is extremely important. Often it is due or die for an RV. Consider how many awesome airstream coaches (non fiberglass) still exist today. I saw one the other day from the 1960 that still looked fantastic (buffed out). It GLEAMED in the sun.
Longevity is very important to me with an RV. Some people keep a coach a while and "trade up" (quotes emphasized), while others like to have the same coach nearly for the rest of their lives (coach includes travel trailer).
Fiberglass roofs indeed are wonderful because somebody can buy one and let it be. Rubber roofs however, will last a good long while but do wear.
It is not the only factor on buying a coach though, but the roof is a very important factor. The #1 factor of warning for anybody buying a used coach is "check for leaks". Fiber roofs are insane reliable to prevent this.
But it should NOT be the only factor in buying a coach whatsoever. Everybody needs to consider their needs/wants when buying - and their situation.
For me personally, since I budget RV a lot and don't have a tremendous bank roll, I go for the longevity. A fiber or solid stainless roof would be more appealing.
Winnebago makes a great coach OP. I don't think you can go wrong.
4 whopping cylinders on Toyota RV's. Talk about great getting good MPG. Also I have a very light foot on the pedal. I followed some MPG advice on
Livingpress.com and I now get 22 MPG! Not bad for a home on wheels.