Bigger motor for the Evora with a blower, should be no contest. The PDK trans really helps the Cayman S out with efficiency compared to the traditional manual in the Evora S and it is also 189 pounds lighter. The Cayman S also happens to have a lower base price.
So which is quicker around the track? The Cayman S. It is more planted, lighter, and just seems to be much more refined. The Evora S just does not feature the same level of polish and seems to be behind technologically as well as the lack of a dual clutch gearbox shows. The Cayman is simply the better drivers car and everyday car. It being cheaper is that much more of a bonus.