I rigged a 40' Hawk with Yanmar 440's and Konrads. The guy had 4 drives brake in less than a year. We finally pulled the Konrads off and put on ASD8's. This was just a 55mph boat, nothing special.

Your buddy with the 525's needs to practice the throttling a bit more. There is a local 36' spectre with 700's and XR's running with no problems. He runs the boat almost every weekend. The drives will last.