When you buy a used MH the best of brands may have problems depending how it was cared for. I think I would be more interested in how well a used MH was cared for, maintenance records, water damage etc.
A lot depends on gas or diesel. Tiffin makes a good MH in both gas and diesel. Tiffin has a fiberglass roof. I like my Monaco gas MH. Also a fiberglass roof. Reading this forum and another forum "irv2" check out some the brands that have big problems posted and be careful. If you see posts where someone has had continued problems pass on those brands. A gas MH will most likely be a Ford chassis with a V10. The only thing different will be the box they set on the chassis.