I like Video Fitness Forum because they do tend to talk about a lot of instructors and workouts besides Cathe, which is interesting if you're looking for variety. Also, their boards are pretty strictly moderated so most of the topics are fitness-related (but not all). That can be appealing at times. However, some of the people there are anti-Cathe for some reason, and that can be really offputting.
I love the Cathe forum for the people, the support, and sometimes even the silliness, but I do wish at times we made a better effort to facilitate the fitness-related topics rather than the controversial ones, you know what I mean?
Marie