As far as the products - useful
As far as the products being used on the recruiting trail - noise
We talk a lot about recruiting on here and we break it down like it's science but the truth is that coaches either like what they see or they don't. Especially when it comes to position players. They either have a good swing and hit good pitching or they have no chance.
If you want to use it to improve as a player then go ahead. If you want to use your attack angle and exit velo to make coaches interested I'd save the money.
FWIW - I didn't think the DK ball was very good.