There will be many interpretations to this answer. I would suggest that one way in which Oedipus is a better man is through the wisdom he has gained as a result of the horrific revelations. He has learned that there has to be a proper respect for the fates that govern an individual and that all of one's free will has limitations. At the same time, I think that Oedipus has learned that his pride did not help him in his attempts. Additionally, Oedipus has learned the nature of the "truth" in his life, the reality that enveloped him, yet laid concealed from him. There was shame in the revelations, but out of this shame has come a new way of life that is more honest and forthright about his state of being in the world.
There is no one right way to answer this question, but it is possible to say a few things. First, he is a better man, because of all his sufferings and hardship. Usually a person who goes through a lot learns much. The school of suffering educates well. In Oedipus' case, he probably would not gotten to where he is at the end of play apart from suffering. Second, we can say that Oedipus by the end of the play really knows what he has done and who he is. The self-knowledge is a true sign of maturity. Before this he was living a life that was filled with lies or half-truths. From a literary perspective, even though he is now blind, he truly sees.