I don't mean to be so negative but this ever-repeated idea of manual focus lenses just "snapping" into focus is such a myth. If you are really critical about focus, no manual focusing will ever match autofocus for speed.
For me it has to do with focus throw. Hasselblad lenses have a long focus throw and many of my Hasselblad lenses are rather stiff to turn quickly anyway. My Mamiya 645 lenses are the newer N lenses and the focus is smooth and fast. I think many would agree that if you can focus any lens on an SLR from close focus to infinity quickly you can see the image “pop” into focus easier as well. Works great on my Rolleicord as well.
