I'm very happy with these bumper plates. They're well-built, look good and are a joy to lift. Definitely an upgrade from the iron weights and wood blocks (to get right height) that I was using. Vulcan has a reinforced collar that looked more robust to me than some other suppliers, and one of the reason I went with them. I debated between the 260lb black rubber and 260 lb alpha bumpers, and decided on black rubber because the bumper diameter is the same for all the weights. In the mostly rare event that I lift outside on concrete, I can protect the bumpers with some small carpet squares. The 10 and 15 lb bumper gives our family more flexibility on exercises that we can use the bumpers. The letter color on the 15 lb bumpers is slightly different shade of white compared to the other bumpers, due to manufacturing process for that size bumper. Other than that little quirk, this bumper set is perfect.