Son's team, playing in the NECBL had some sick HR numbers this year. They also used Diamond baseballs. Both the team and an individual player broke league records for HR's that had stood since the 90's. The team tied with another team at 73 HR's in 41 games and the individual had 19.
Not fun being a pitcher this year in many of the college summer leagues. Not sure what the point of changing the baseball would be.
Just makes the summer leagues somewhat irrelevant to MLB...