and does very well( but he's a machine with any of his guns). It all goes back to ergonomics; what fits you best. I shoot better of an elastic knee pad on my arm, just 'cause it puts the gun in the best position for my body. Off the knee puts the gun way too low, although I've seen pics of shooters with their heads appearing almost upside down, or maybe they're shooting cross-eyed. Like what is said in the thread above, try the positions, improve your physical condition and practice practice practice to learn muscle memory as well as technique.
I love my 6-24 Bushy. The practice helps here too as more experience ranging goes along with improving everything else.