Just to add what I have experienced. Had to get new rubber early last year and the 2 sizes of PR3s I needed weren't available yet. So the K100RS got Michelin PR2 and the R1100S Power Pilot 2CT. As a direct comparison- the PR2 feel good as all around ST tires. Jumping onto the R bike- the PP tires feel like they roll (transition) from left to right turns (or the opposite) much easier. They feel more round from side to side. Maybe that is just how they were designed?