If more than $USD 10,000 it must be declared to Customs upon entry and that could slow you down. If you have a stateside bank account, you (better with help of Chinese citizen) can electronically transfer funds to that. A higher limit applies.
Only speculation that US expats outnumber Kiwis here. But we'll all soldier on, and benefit from information called for by the first post. If we can keep this friendly, other posters might feel unafraid to add their experiences.