I use hangups at work as well. There are many shortcomings though. I suppose you use it with a.bunch of friends, say 16 persons. Quite easy to select each one of them in the contact page. Were almost 200 people at work, and people create new "temporary" groups all the time to talk to multiple persons. I just cannot scroll in nearly 500 conversations when I need to talk to a specific person...

You cannot create groups either, or add contacts, or close conversations correctly (i need to close them twice)

So for now, I still consider IRC to be the most mature text conversation system.

I've been working on ratox as well though, and I must say I'm pretty enthusiast about tox, but the UID contact system will slow its adoption for me...