I think it depends on the forum, and can be effected by the topics it focuses on, how well moderated it is, etc. Way back before ABC took it over there was a public parenting board associated with Go that was really lovely. The moderator knew how to work with people who were having trouble getting along or understanding each other, and was always able to smooth out any conflicts. She also knew the topic inside and out. But, after all the ownership changes, ABC didn't see the value in keeping her on payroll for just that one forum (yes, she was actually paid, can you imagine?!), and shortly after that closed the parenting boards completely, and eventually went to auto-moderation for most of their other discussion boards (posts get deleted if enough readers click on "report." Easily manipulated by gang behavior).
I still belong to some private boards that are really nice, but you have to survive the public boards first, build relationships, and then get invited (assuming someone on the public board is interested in creating the private one). In the world of twitter and facebook, however, many of those are closing up or getting stale, however.
Other places are never as interesting as this community, however. People here see things in a very different way; I've learned a lot from it.
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Mom to an amazing young adult AS son, plus an also amazing non-AS daughter. Most likely part of the "Broader Autism Phenotype" (some traits).