Chat rooms aren't all that they are cracked up to be. I run an outdoor forum in which a chat room is available, and I have also been on other forums with chat rooms, and at first, they are hot additions but eventually they will die down. Now, nobody uses it at all.
I will say that the only way to get the most out of it is to schedule a "weekly" or "monthly" chat session and maybe talk about your upcoming events, news, etc..
Good luck with your decision.