^^^Tennisfan - that's a whole other debate right there! Tennis pro's all over are fighting over the merits of ROG!
Not speaking for Julian, but the simple answer (from my experience) is that yes, graduated racquets and balls do improve the speed at which the players can acquire skills, but they must be tied to an appropriate court size to be effective (hence the ROG systems). Whether you believe that is the best way to develop a player or not is another debate for another thread!
I tweet - @ashtennis guru (no spaces)
I Shoot - www.flickr.com/photos/ashtennis guru/ (again no spaces! grrr)