Metabo FTW, broken clutches, electric brakes, even chucks with constant 140mm hole saw abuse on everything else I have tried, most recently snapped the chuck retaining bolt on a Milwaukee that was 6 months old. Keep busting out the 8 yo metabo every time one gives up, and it just takes it. Metabo ftw I should add the metabo has started jumping out of gear now and again but it has still outlasted, Hitachi, Milwaukee, AEG, Panasonic and Ryobi. In my experience anyway