Sam, sounds like you are doing good. You know, for a moment I thought your xH and mine are similar - but the difference is that you FEEL he is being sincere. He may still have his addiction, but you could tell that he wanted reconciliation b/c he wanted to be with you, not b/c he wanted to use you.
I think the space between you and xH is a healthy boundary. You both know what needs to be done before you can get back together. Keep up the good work!