If you are meaning a SS tire over an ST...I would argue that at street operating temps, 97% of riders would never exceed the grip of a ST tire. I've gotten an Angel GT to slip in a corner a couple times...and I was purposely trying do it. It required an extreme lean angle and WOT, which probably isn't on the menu for the majority of riders.
In fact there are many cased where a modern ST tire will have more grip. Cold weather, cold tires, wet, less than perfect road conditions, etc.