On the one hand, Priester was the higher draft pick and generally more well regarded as a prospect, so his stuff was more obviously apparent.
On the other hand, “stuff” is generally correlated with getting strikeouts, and Myers has a clear advantage over Priester there.
Its really just two different kinds of stuff. Priester is a little more old school working everything off the sinker down and Myers a little more from the new school of mostly working off the four seamer up.