The difference between season 1 Saul and season 4 Saul is amazing. All the stuff he went through, finding Helen, losing Helen, finding out he's a cylon. If seaosn 1 Saul had found out he was a cylon he probably would have done something rash. By season 4 (well...the end of season 3 technically) he had grown to love the entire crew so much that he didn't have to define himself as a "toaster".
Love it.