Actually, that's not completely true. DVDs, unlike CDs are not vulnerable to scratches on the label side. This is because the reflective layer/dye is sandwiched between two 0.6mm layers of polycarbonate, whereas as the reflective layer on a CD is right at the surface, usually with an extremely thin layer of lacquer or similar.
Having a branded surface really has no effect on DVD media. However, some people, like myself, prefer branded surfaces because unlike shiny silver surfaces, they repel fingerprints and dirt.