I don't mind the queue times because it feels that much more important that you do well when its finally your turn, or you're just stuck waiting again for same boss. 20 mins or so at peak times isn't too bad for me, but the more invites that are sent out or "free" will make those times even longer. If anything though, I notice some people just don't care for waiting that long and give up and leave, making my wait in line that much shorter.