Which is the best interior design studio in Beijing?

I know a designer named Jiang Jianye in Beijing Independent Design Studio. His design is very good. From the owner's point of view, the products he chose are cost-effective, simple in atmosphere and good in designers. Teacher Jiang promised not to take kickbacks from customers and made money clearly, and our whole family was grateful. Among several customers I know, he has a good reputation. So my family decided to let teacher Jiang design it.