I tried the search and wasn't successful finding any existing threads on the latest version of the PR4 Trails. I have the PR3 Trails on my 2012 GSA and have been very satisfied with the on road performance. I have about 7,500 miles with a lot of two up almost exclusively road and several trips packed fairly full. The rear is getting fairly worn and flat in the center. There's still some tread good tread but I wouldn't ride off on a long trip on it. The front has lots of tread left but I like to swap tires in pairs. So, to get to my questions. Has anyone installed the PR4 Trails yet? I saw a review that says different center/harder compound for better mileage.