are you lowering player speed using MtRun ? If so, you should raise it back a bit.
jump speed is more determined by speed & net presence skills than by the jump bonus depending of style (except for the volleyer where it's equivalent of 100% in both skills).
I could replace the jump speed bonus by a ball difficulty modifier during the jump, but that would be harder for me to tune it effectively, and harder for the players to feel how the bonus works. So I think the current mechanism is nice enough while not creating anything utterly unrealistic (ie: nothing like over speedy players).
plz manutoo don't make every day verision plz