I'm repairing 18-20 years currently . I hate EVERYTHING that has to do with drywall. But this mill saves lives. I've only used it twice and hope it lasts. Now when sanding the dirt in the pocket, use a low grit sandpaper. 60-80. for a round orbital nozzle, roughly halve the speed. With a triangular attachment at full speed, still with 60-80 sandpaper. This thing is going to get REALLY close at all angles. But you still have to go back and sand the corners manually. The suction power is not the greatest. But for the price and compared to manual grinding, there is practically no dust. The holes where it sucks are a bit small. Now the grind plus 3 buckets of dirt is a whole different beast. Plus 3 is very dense compared to bag sludge. So I noticed that the coarser grit grinder works best. 150-180. You need to slow down and open the suction port at the end where it connects to the hose. The main thing about this electric mill. You really are worth the money. If you adjust properly to your sander, this machine will definitely cut your drywall installation process in half. That is for me. And I don't fly a shitty carpenter at night. I take pride in everything I do with my work. Even if I don't like it. When I'm done, the walls will be perfect. You will definitely get your money's worth by purchasing this grinder.