I spoke to my luthier last night during my lesson (he is also my instructor) about your query. He stated that the closer you are to the end of the fretboard, the richer in harmonic content the sound becomes along with the resultant rich, full-bodied sound (hence the reason many jazz boxes have a pick-up suspended or mounted at the end of the fingerboard). Conversely, the closer you get to the bridge, the less the harmonic content becomes with the resultant thinning of the sound.
He also stated that pickups can be mounted anywhere between the bridge and neck, depending on your sound preferences, but that they are usually located at points where strong naturally occurring harmonics are present. He's had guitars he's made where the owners had him temporarily make the p/u's movable so that the preferred positions could be determined by playing and listening. Obviously, sonic beauty is in the ear of the beholder. The p/u spacing on a Strat isn't normally tampered with due to the magical interaction of out-of-phase magnetic fields that can result in that magic Strat bell-like tone.
Garcia used to have plexi P/U plates on his Alembics in order to quick change them and for optional placement. If I'm not mistaken, Jack Casady had 'activators on moving rails (tubing) so the p/u position could be varied (on Alembic #1?).
My personal opinion is that if you want a warmer, less-trebly/harsh guitar tone, then go for it!
