How long you might have to wait is so unpredictable these days that I go for a separate trip to pick up the ticket. (Though at Beijing West South there is a separate window if you're picking up a ticket for a soon-to-depart train.) Remember, you can pick the ticket up at any train station in the departure city without paying the 5RMB fee. Remember, too, that ticket issuance stops 15 to 30 minutes before departure, depending on the station. Ticket checking also stops about 10 minutes before departure, again depending on the station.