Hall of Fame
Fed Nadal and Djokovic all learned with the old rackets and they're dominating the players who grew up with the new rackets. The old rackets taught you to hit the ball in the sweet spot and hit flat and hard. Should juniors play with the old rackets until they're ten, to learn to hit flat and hard and in the sweet spot? Before you say it would hurt their development to switch playing style at ten, consider that it didn't hurt any of the big 3.