I am a member of Anton's group on FB. There is far more activity there than on any APUG group. That includes posting photos.
I don't really understand the FB hate. It is what you make it. It doesn't have to be intrusive on your life. I have had really good experiences with FB in sharing my art with people and finding long lost friends. It is easy to remove anyone or anything from your news feed. It is easy to share stuff with multiple people and get lots of feedback and conversation from people all over the country or the world. It is far more personal than APUG. No one makes you spend a lot of time on FB and you are not obligated to look at all the posts. I have sold work off FB. That has never happened on APUG. I like APUG but look at only a very small percentage of the posts. APUG is on FB by the way.