They practice medicine, no such thing as settled science, & the wheel is always being improved. I love the old stands except sometimes small targets spin off, these new stands improved & I think there is a solution for target spin off looking at the new stands. These leg stands are the only way to go for set up and take down. I purchased these so I could set up and practice. Brad's KYL is so very excellent as are all of the products I have purchased from him.