A good cycling friend always swore by Assos. I was turned off by their high cost. I ended up buying the Large S5 from the Assos Factory outlet was they were the same price as the PI I have been using. What a big difference. The Assos are designed for the on the bike positions. They just make the miles melt away on long rides. As my PI are starting to wear out, I will be replacing them with Assos.