Just to clarify, I don't know much about the origin of Ultron, it's just what I've read while the film was being produced, it was only when I watched the film, that we find that Ultron Plays a part in Visions creation.
I have always believed that Vision was part of the Avengers and had nothing to do with Ultron.
So I'm with Kernie with the good guy/bad guy theme on this one, and Vision should remain on the Front

Let the Comic Book Nerd battle commence