My road bike has 25mm GP4000SII's and my do it all bike has had 35mm Schwalbe G ones and 30mm Schwalbe S ones. Using both bikes for the same ride, there is not enough difference between the GP4000 and S ones to be a factor, the 35mm G ones made a difference that was noticeable. The Schwalbe are great for those patches of loose gravel that gather up in corners of some roads, it's like they have the ability to glue themselves to the traction underneath, but yes they wear pretty quick if you are just using them on pavement.