I think that you need to define “heavily post processed”. It is obvious to me that Bryan’s pictures contain post processing. “Heavily” to me would imply that he went in Photoshop and manipulated the sky. I doubt this is the case in these pictures, what is more likely is he used DPP to convert the pictures from RAW and no doubt applied adjustments. I think if you want a lens by lens comparison you need to look at the ISO charts, not at samples that are used to demonstrate what a lens can do, obviously with Bryan’s skill level.