Cyrus Lee at ZDNet reports that iPhone 5c and iPhone 5s units bought in Hong Kong will not be supported by the Apple warranty for China. It seems that the iPhone 5s model numbers for devices sold in Hong Kong are different than the model numbers sold in the rest of China, as are the iPhone 5c model numbers.
The prices in Hong Kong are lower than the prices in China, so Lee expects this potential service and warranty problem will not affect where Chinese consumers purchase their new iPhones.
This information came through an employee at a Shanghai Apple store and the original source is a NetEase report written in Chinese, a beat covered by Lee. He also writes that the gold iPhone 5s is popular with Chinese consumers, but availability is limited.