I definitely wouldn't expect 'Walter White levels of transformation' for Saul. After all, Walt had a family, a wife, and a teaching career etc. The alteration in character that Walter went under to eventually
be Heisenberg was huge. Whereas Saul, on the other hand, has always been sly, as well as always having the potential to do anything morally 'bad' for his betterment.
Perhaps I'm having a hard job remembering the early Saul from Breaking Bad then, or maybe I'm expecting Walter White levels of transformation.