works perfectly for me on a site with 6,000 users, though I do have my own dedicated server, 2GB Ram, Athlon CPU.
Only one thing I found troublesome, maybe not to do with the chat mod but FRAM, if I make a friend request, it seems the chat will not work if they do not also make a friend request back to me.
I.e. I make friend request, they accept
Chat still does not work.
They then make friend request to me and I accept
Is this a wierd thing around Fram or Chat?
It would be better once a friend request was accepted, it worked straight away.
Apart from that, it is a brilliant mod and has kept my users online, increasing the time they spend on my site and not on others, hehe