I bought these mounts for two specific reasons-their adjustability and durability. I recently purchased several steel plates to practice for Steel Challenge. These mounts are perfect b/c I don't have to precut my 2x4s and I can level the stage even when the stands are on uneven ground. The AR500 hook and hanger will likely last a long time. The shipping was also super fast and I placed my order online.
To help those who follow, I had purchased my steel plates from Shootsteel and my particular plates have a cross shaped hole that I was worried wouldn't work with these hangers. My concerns were misplaced as you only need to rotate the plate 45 degrees and the 3/8 in hanger hook fits perfectly through the hole and then hangs straight.
I would unhesitantly recommend these mounts to a friend.