Changed man?

I have been reading your posts and comments about how they say how much they have changed and what wonderful guys they now are. Mine has been doing this over several months. He says if only I could have shown you the man I am when I am with her(ow). Is this all crap? What I am reading is that it is all BS. But I still in the back of my mind wonder if he couldn't be the man he is today because he was just not into me any more after 20 yrs of marriage and children. Sometimes I worry I might take him back to see if he is this changed man he's telling me he is. I think the OW thinks he is wonderful. It has been 6 months. How long will she see this side of him. I know there have been moments of uncertainty for her as well.
Thanks again everyone, it is great to read your thoughts and ideas.