I'm sure part of M's parenting style has to do with not having as much time with his son and trying to assuage his parental guilt over the divorce.
I know you long to be in a living-together situation because your marriage was so brief and unsatisfactory. But don't rule out long-term dating but living apart. That might be the easier option with two such different parenting styles. At the very least I would wait another year or two before considering living together.
