I've been booted twice in the last hour because of a weird error. The game starts lagging terribly, and after a few moments I get booted for spamming the chat. I think the problem might be that all my attempted commands (IE trying to put up a shield before a skeleton kills me) go through at once and the game sees 10 attempts to use the same attack.
So the real problem - random, horrible latency. This is the first I've had issues outside of busy times.