I've messed with it, never shot behind one though. It's an interesting concept, but the problem that I see is with canting the stock. When the ring is loosened and the stock canted either left or right, you are moving your finger away from being lined up with the trigger. The ability to cant the buttplate is nice, but the weight of the chassis is around 8-10 pounds
Have you ever looked at the Ashbury chassis? It has a ton of adjustment as well as shoulder LOP adjustment and trigger finger LOP adjustment. 6.3lbs for the MOD-1