what is the difference between the Bifeng Gorge Base of China Panda place and the Chengdu reserve

I think the big different is that the Bifeng Gorge is more natural and the Chengdu Base Center is just a park.

But based on my experience, I prefer to the Chengdu Reserve. It is much closer to Chengdu city and have more comprehesive knowledge about the pandas. It has more pandas than the gorge base.