This is the next jig in my shop because of the inherent inaccuracy in a sliding compound miter saw. Any lateral force applied to my particular saw can affect the line of the cut. Likewise how you press down into the cut also affects how well the resulting miter will line up. This is kind of a deal breaker when trying to make air tight miters. Many woodworkers swear by the miter sled. I hope I will too after making one ;-) Probably a shooting board for the final sneaking up on the line, too!