Thanks for the info. Based on your answer would it be safe to say that since baseballs approach the plate in a downward angle and softballs (for the most part) approach the plate at an upward angle, that an up-slope swing is preferable in baseball and a down-slope swing is preferable in softball.
By the way - feel free to continue with the "info overload" - the more knowledge, the better.
I am afraid it would not be safe to assume "that an up-slope swing is preferable in baseball and a down-slope swing is preferable in softball." First, I would point out that the release point for a submarine style baseball pitcher is much lower than the fastpitch release. I have not found any change in the batter's swing mechanics for a high or low releases. This is true for both baseball and fastpitch.
Sound fastpitch mechanical principles are the same as sound baseball principles.
FastPitch/Baseball -- side-by-side