Thanks, Dave! The problem with Lu's statment (as he transcribed from that little blue book he always quotes) is that he has it backwards. The twist evens out the lift across the blade's span, and makes the helicopter carry more weight for the power. Twist is secondarily a stress reducer at the tip, but a stress raiser inboard. The max twist on an aluminum blade is about 10 degrees because any more will cause the bending load to be too high. With twist, the inboard sections of the blade loses stiffness since the twist permits buckling which vastly reduces the strength of the blade.
The twist is used in hover primarily, and low speed flight. At higher speeds, a variable twist (recall those piezo-electric tabs) is best, where the lift distribution can be kept perfectly even while the blade whirls around the mast, going upwind and downwind.