Actually, the answer is likely to be to go to a bank for the best rate (Bank of China, China Construction Bank, Agricultural Bank of China (ABC), and the Industrial and Commercial Bank of China (ICBC).are the big banks there). Between airport currency exchange and hotels in China, I've heard that hotels are typically better than at airports.
Most travelers to China, including myself, just withdraw yuan as needed using ATM/debit cards - there are ATMs that accept foreign cards all over the place. You likely will get hit with a foreign transaction fee (usually up to 3 % of the amount withdrawn) and possibly an out of network fee from your bank but the convienence of not having to carry large sums with you somewhat offsets the pain of the added cost.
Check with your bank before leaving if planning on using a card overseas to confirm what the costs are and to notify them that you plan on using the card overseas as most requrie a foreign travel notification. If planning on using a debit/ATM card, you might see if your local bank can exchange one or two hundred dollars into yuan (or do this at the airport prior to boarding your flight), so you have local currency with you when you hit the ground in China for food and transportation until you can get to an ATM.
You can also shop around for banks that allow withdrawls on the best terms. For example, I have a card through my Schwab brokage account that reimburses any fees charnged and some banks may do the same.