I remember being in his shoes and having the same questions but i had little to loose at that time and if it didn't work out I could always go back.
One thing is for sure, there will always be a "what if" question going on in his mind if he doesn't make the move. I had it and it only went away after I made the move. Many people told me not to do it and now I know why and unfortunately they were all right. If I had a little more patience, I would've been better than I am now.