Oh, shoot a Benelli M1 Tactical versus an M1 Montefeltro, and do it on a shot timer. The benefits of that grip are immediate and easily identifiable. I use one on my 1100 and have not timed it, but I like it more than the old English style stock that was on it. You get more positive control than with a standard stock.
I have to agree with the rest of your post, Sir!