I've waited at times and other times I've walked right in and up to the counter. The thing I didn't like is they don't accept debit/credit cards or checks if my memory serves me correct.
We went at 1:15 on Tuesday and waited until 4:15 and had to leave because the computer system went down. Today we got there at 9:00 and our number was called at 12:25. Took 5 minutes to complete the picture, fingerprints etc.