Actually I'm on 737 based in Haikou more than one year now. As 330 you can be based both Beijing and Shenzhen but Shenzhen is almost impossible for you as new. On 737 you can be also in Guangzhou and Shenzhen, again Shenzhen very hard to get.
Spend with your family few days in Beijing and then decide between resident and commuting contract. My choice is commuting but depends on many variables