Aluminum, step up, Sundowner. Sundowner has a patented floor called Rumber. It is black, a rough texture, made from recycled tires, livestock won't slip, and it comes with a lifetime guarantee. It's not like a Featherlite that has rubber mats on top of a metal floor. The Rumber material is the floor. Also Sundowner welds all of it's bows that hold the roof. Most other manufacturers only weld a few of them. Also door hinges on a Sundowner are completely welded on, not spot welded or riveted on. That's just my opinion.