I went to Al-Anon regularly for about a year in all after I split from my AXGF. I haven't been back in a while due mainly to childcare commitments and partly because I haven't really felt the need. I still keep in touch with some of the friends I made there; sometimes we talk Al-Anon, most of the time we just catch up about "normal" stuff.
At the time I went it did make a difference and I did get a lot of support from the meetings. That support, and that feeling of not being the only person in the world experiencing this, was hugely important then. Personally, I think I got more progress from one-on-one counselling as issues could be explored from different angles and in a more interactive way.
Mr B.