I've flown in and out of both Beijing and Shanghai - never had a problem. In fact, on the trip to Hong Kong and Beijing last October, I had more hassle at the TSA security check at Newark Airport than going through immigration and customs anywere along the way.
Years ago (1971), I visited Indonesia, entering the country through a remote airport in Sumatra (Pekanbaru). I had been told that it was wise to have the customs dudes write the pertinent data on my photo equipment in my passport, and then stamp the page to indicate that it had all come in with me. Was that ever a mistake! Took forever to get them to do it, and then it was a major hassle when I went to leave because then they wanted to inspect everything on the list to make sure I hadn't sold anything on the local black market.
Since then, I just throw the bag over my shoulder and present my passport - and I have never had a problem with photo equipment since.
Although I do have a few "war stories" about other kinds of things that caused local customs dudes to have gas. Like the time the guy in Libya confiscated the copy of Ana Karenina that I had been reading on the plane just because it was in English rather than Arabic.