I've been going every year since 2005, and AZ has grown far beyond my expectations. If it had stayed as small as it was in 2005 and 2006, I probably would have stopped going by now. Every year I see the attendance go up, especially when it moved to the Raleigh Convention Center.
Granted, with that many more attendees, things can be a little more hectic, but I still run across some of the same people I saw in the beginning, and now there are more people all around (which means a variety of photoshoots).
I don't think AZ will ever be the same as Katsucon or Otakon, due to its location and its relative obscurity to people outside of these handful of states. But you never know... it has grown pretty fast.