I popped into the Customer Services centre this morning after an early morning meeting. I was checked in at 9:15am and was seen at 9:23am. There were four people waiting in the whole centre, two of whom were waiting on the issue of parking permits. There was one cash window open serving one person so there was no queue there. Everything was calm and businesslike.
Chatting briefly to the agent I saw they recommended avoiding the start and end of weeks if you want a quick visit. Also avoid the the end of the month.