Hi Werner,
Nice website.
For what it's worth, I play a medium scale Essence and a short scale Brown Bass. I had a long scale but, as I told Paul (TBO) I got tired of chasing it around the room. From long to short, yes, there is a difference between frets and you will most likely notice that right off. But for the tone I think it is important to consider the woods or which the bass (particularly Alembic)is made. My Brown Bass is stock walnut, & myrtle with a walnut(center piece), mahogany (outside pieces) and maple neck (two laminates). Those woods make that bass very deep in tone by comparison to say a bass with a mostly maple neck. It seems as thoug you almost have to push the Brown Bass to get a really bright tone. Point being is that if you have the opportunity, play some with different woods.