DxOmark (Click here) tested the new 20mm f/2.8 E-mount lens. They didn’t test the “older” 16mm pancake so we can’t know if the new 20mm lens is better. Obviously the lens can’t match the quality of other more expensive primes like the 35mm f/1.8.
I still think Sony should do a tiny bit faster and a tiny bit higher quality pancake. I know, it’s easier to be said than made :)