For 20 years I had an elite body shop. On the floor were two types of air powered random orbital sanders. One was a DA side handle and the other was a paddle just above the top of the grinder. This type of paddle allows you to focus on keeping the sander level so you don't dig any grooves or voids in your work. It's not that the DA's side grip/arm couldn't do it, it just didn't make it as easy as this one. The craziest thing about this grinder is the price. Common floor grinders cost a multiple. For the price, I knew I was willing to take the risk and I'm glad I did. It is smooth. Be sure to add a few drops of air tool oil before each use. Another approach is to add a few drops when you're done with it and skip it a bit so the inside is soaked with oil and it's ready for the next use. In general, a spare tire is great even if you already have something similar.