It's always nice when I sign up to a forum (especially a big one) and see it using Xenforo. This happened to me today with MacRumors. Guy who used to help me run a big forum used to say he wish we'd founded MacRumors. I didn't listen at the time, but I see now it's really huge and nicely done.
Anyway, congrats to the Xenforo team, especially given what I've gathered about the initial birthing pains.