There is an HSBC ATM just inside the customs area, just to the left of the "green/nothing to declare" exit, which I used last week rather late at night and it worked fine -- despite a mildly scary English note giving you a phone number to call if it ate your ATM card.

The advantage of using the ATM inside the secure/customs area is that there are no touts, pickpockets, or other scum there to see you use it.

There was also a large boxed in area upstairs before going down to customs that said "CITIBANK ATM to be HERE IN JUNE," but as I was there on June 4 and the boxed in area was still boxed in, and it is China after all -- it might be working or might not be by the time you get there. However, look out for it.

P.S. The entire maglev ride is 8 minutes, not 15.