One thing I noticed when swapping to winter tyres, is that the circumference grooves (water channels) are no where near as deep nor wide on the PSS compared to the GY F1s.
That said, I think they shouldn't be compared, IMO the PSS is an all out performance and tuning tyre for lighter cars ('Rari, Porker and M cars). It breaks away too quickly on the C5 where as the GY F1 continued to grip and cope better, probably because these can shed water better.
GY F1

Vs.
PSS
