The focus of the group is healing childhood wounds and looking at the family patterns that were passed on from generation to generation. Since there are a lot of overlapping issues in families with a pw BPD and families with alcoholics, the groups can be helpful to both situations.
That's basically the overlap in *everyone's* issues, codependents, nons, cluster-B's, everybody. Unless you're one of the singularly rare people who grew up in a 100% healthy home, you basically at some point have to do this work.
Most helpful to me? Going through the steps with a sponsor helped me to get into the issues. Groups are helpful too, but I think a sponsor really helps to do the personal work involved.
I did group therapy, and having a variety of outside perspectives is GREAT for personal accountability and gauging what are reasonable expectations to have for oneself in these tough situations. I never did 12-Step, but I know a lot of people who did/do, and I've seen it really transform people for the better.