He is a good boxer, one of the best in the division. Heavyweights (in this era) are not really known to be combination punchers, but Ortiz can actually do some things and his reach is pretty ridiculous for his height. But while his hands aren't slow, he still seems lumbering and sometimes inactive to me, just because of his size and build. Sometimes I wonder if the steroids were giving him just enough explosiveness and stamina to use his superior boxing skills to his advantage.
If he's clean and slower as a result, Wilder may keep his at a distance and outwork him, occasionally landing big right hands. I don't see a 38 year old guy that is built like Ortiz having the kind of stamina that Wilder has now that he is clean.
Wilder will not want to get in close though, Ortiz is just a more polished inside fighter in every way.