I've been through PuDong several times. Only once has customs had any look at me--and that time I had a cart piled with 4 big suitcases but no carry-ons and was apparently alone. That drew the interest of the customs guy and then the fact that my passport stamp was two days earlier drew even more interest.

At that point my wife showed up (I had walked on ahead to get her to quit spending forever talking to the lost baggage office after we had gotten our bags.) and explained what had happened (our bags got left behind in LAX, we were picking them up.) The bags were run through the x-ray but that was it, nothing was opened.