I would not let the roof be a determining factor on the purchase of a MH. TPO (Thermoplastic PolyOlefin) is a thermoplastic materiel and more durable than the EPDM rubber material which will slough off the white surface over time and eventually the black rubber will show underneath if left untreated. Personally I would prefer a TPO roof over the other roofing systems FG, EPDM or AL. EPDM would be at the bottom of the list but having said that my rubber roof is going on 20 years old and has not torn or leaked and was treated once with Cool Seal about 9 years ago.