Game mechanically it is pretty much the same. But characters in savage worlds are build in a different way than units in showdown.
Basically the super companion (don’t have it yet, mind you) has a lot of edges (like feats in dnd) and advice on how to run a supers game, tough it could be useful to a supers showdown game, its not plug and play, so to speak.
There will be no point costs for the alternative power system in the supers companion, so balancing fights would be hard.
So tough you might get some good ideas from it the main future of the supers companion (the alternative powers system) would be of little use.
That all being said, there are a few things I should also mention, first of most of the powers in the super companion can be emulated in one way or another in showdown super speed, reflexes, strength, toughness, entangling, blasting, etz are all there.
Beyond that there will at some point be a showdown companion that will presumably expand the options further thus probably covering even more.
Does that answer your question?
EDIT: As a side note, I would totally be up for whipping up stats for all sorts of super characters at request.