What can I say? They get it done.
My advice? Prepare all your documents in advance (they need to know where EXACTLY you are going, where EXACTLY you are staying, and how you are getting there.)
Make an appointment. Tell them you made an appointment. (When I went there they didn't ask and put me in the non-appointment line up which took much longer.)
Give yourself enough time. You're handing over your passport for a week. Don't push your luck with your timelines.
Then, get your passport back, and head over to China!