I have the chat and mobile chat. It's the best and the support is second to none. 100% happy :)
Will cometchat be available for alternative payment options besides a credit card? I used it before on another site, but am unable to purchase it to try it out on Ning. Also, I am reporting a bug with it on a network that has used it on Ning. On the "Create Your Profile Page, it thinks you are a signed in member when your membership has not been created yet. It allows anyone whose not yet pending approval to join any chat features available to all members, however it does recognize on any other page accept that particular page when first creating your profile out of all the pages, that you are in the processing of pending approval.
This only tends to happen if members click to sign up with an alternative profile like facebook, google, yahoo and so on.