I wonder if those players swinging 28-30 oz bats ever check their bat speed with a radar device. Then compare results to speeds with a lower weight bat.
About the same. Maybe a little faster with the heavier bat, since more mass is going through zone. EL bat help speeds things up too, with some weight at the end.
Bat Weight and Batted Ball Velocity
To see the effects of bat weight and bat speed, here is a summary of an experiment that I found summarized in a 1980 high-school textbook, Physics of Sports developed by Florida State University.[6] For this experiment, the ball mass, pitch speed, and bat swing speed were all kept constant. Only the bat mass was changed.
The data shows that a heavier bat produces a faster batted ball speed. This makes intuitive sense since a heavier bat brings more momentum into the collision. Doubling the mass of the bat results in an increase of almost 12mph. So, using a heavier bat should result in faster hit balls, which means the hit ball will travel farther. If a player can maintain the same bat swing speed with a heavier bat, the heavier bat will produce higher batted ball velocity and an increase in distance.
But, any player who has experimented swinging bats with widely different weights knows that it is easier to swing a light bat than a heavier bat. Put another way, it takes more effort to swing a heavy bat with the same speed as it does a lighter bat, and most players cannot swing a heavy bat as quickly as they can a bat which is half the weight. So, we need to see how the batted ball speed depends on bat swing speed