The last time I visited, that group had 800 or so members, but Facebook is a horrible interface for discussions. Multiple nested sub-threads, it's easy to miss posts and makes following discussions difficult.

In addition some posters limit their post visibility to "select" group members, so you might see a post with 50 responses where only a few are visible. The format on this board is far better and it's a pity more people do not abandon FB and post here or the other Boardhost forum instead.