One thing that isn't in dispute here is that some other tires are in fact more durable than GP4ks, like Gatorskins. That being the case, people who are concerned should test ride some gatorskins to see if they can even notice a difference. I know the GP tires save watts and are lighter and are more supple bla bla bla, and I also know some of us actually can feel a difference, but not everyone can and for the people who don't even notice that they're on the more durable tire, why not just stick with those? They're cheaper to boot. One of our local Cat 1 fast dudes who wins all the regional crits trains and races exclusively on gatorskins, so it's not like you're suddenly riding around on blocks of ice if you switch.