This is a great question that comes up often and while there isn’t one correct answer, let me share the pros/cons on each option:
Existing Forum – By joining a group that’s been together for a while, they’ve already figured a few things out. They have a system that works, and you get to plug in quickly to that system. They probably already have core values, a set schedule, and roles assigned. The advantage is that you don’t need to figure anything out and can get going right away. The disadvantage is that they might be stuck in their ways, and so if you don’t like the way they do something, it might be harder to create change. The group will most likely already have many inside jokes and shared experiences from past meetings or retreats that might make you feel like an outsider at times.
New Forum – By joining a new Forum, you start fresh with a blank piece of paper. You are an equal voice in the creation process. If you don’t like something, you can easily suggest and change it. Every part of the Forum will have your fingerprints on it because everything is newly established. The disadvantage is that new Forums take time to get going. It takes time to set up the logistics, learn the roles, and flesh out the process. Also, because everyone is new, deep relationships probably don’t exist yet. It will take time for the group to bond with each other and build up their social capital.
So which one should you choose? It depends on you! I’ve seen both work, and I’ve seen both not work. My suggestion is that if you are interviewing with an existing forum, bring up some of the concerns I share above, see how they respond, and then go there.
Lastly, remember that sometimes the group’s issue has nothing to do with whether it’s an existing or new Forum, but rather with the people within the group. So either way, you pick, make sure that you like the people in the group first and foremost.