Saved a lot of time and effort. Although it's very difficult. It's amazing how quickly the device sands down the walls. A good, powerful industrial vacuum cleaner will help reduce the amount of dust, but with this device, the entire area will be covered in dust. Clean the filter of your industrial vacuum cleaner regularly and be sure to wear a dust mask. Be very generous with the dirt as it will help hide the transitions and make the wall seams flush so you can't see them. Don't worry about getting the dirt clean or smooth, just apply it. This device smoothes it out in a stroke or two. I loved how quickly my basement drywall was completed without a lot of time and effort.