I dunno. I'm not often on it, but there's something cute and quirky about Forumotion's chatbox. And you have to make an account for it, if you don't have one already. But it's good for not kicking you out of the chat, so you don't spam it with dots, and you can lurk without a problem. But then you don't know if they're acctually there or not, like you do with the forumotion chatbox, where you have to make a conscious effort to log in. And chatango has sounds.
...Having said that, my answer is 'Dunno.'
How helpful. :I
(On a side not, could you make the 'new post' icons a little more obvious? I keep missing them. ono)