I had one (MBA-3) but sold it and switched to a Magpul MOE SL. Depending on how your AR is set up but for me it had to much adjusting each time using it. I had to tighten it each time. Need to be careful with the screw, some have stripped it.
I have the MBA-3 and love it. The screw takes the last little bit of wiggle out. If you don't care about the last little bit, you don't have to use the screw at all. My stock is tight without the screw so it works just like any other adjustable stock. The most important part for me is the adjustable butt plate. With the butt plate slightly out it gives me a length of pull which is between the standard holes and feels natural to me. I also place the butt plate all the way down and to the right, I can finally get most of the butt plate/stock on my shoulder. With most other stocks only the bottom half of the butt plate is on my body and to far in toward my pec. I have wide shoulders and a long neck this is the first stock I have tried that feels natural to me and places the scope right at my eye.