Derek, look forward to the report.
Your comments are interesting, I can see the 997S advantage on track where PASM offers you two cars in one, the sport mode does rather endow the 997 with near GT3 levels of suspension settings/handling. But this is (for me anyway!) too firm for the road, so if you don't do track days how does the "S" in standard PASM settings compare handling wise with a C4S, can't see there would be much in it, although the 997 clearly has a power to weight advantage. Interested in your comments.
Just as a matter of interest below are the track/tyre comparisons between the two, for what it's worth the C4S does actually have a wider front track than a standard 996Carrera (by 7mm) although clearly, as you say, no where near as wide (at the front) as the 997.
Track
C4S F-1472mm R-1528mm
997S F-1486mm R-1516mm
Tyres
C4S F-225/40ZR18R-295/30ZR18
997S F-235/35ZR19R-295/30ZR19