Wiring Q: switched neg. or pos. which is better?

[mk1mark at gmail.com (Mark F.)]

Hi List, the 75 Scirocco I'm preparing for road/track duty was
completely rewired by the previous owner with a Painless Wiring kit. 
It appears that he has installed everything switched positive.  I seem
to recall from info I read years ago that switched negative is a
better way to wire a car.  This true?  Should I go through the trouble
of changing everything (I'm about to go through the entire harness
anyways - I don't really like the way the guy did his work, looks
hurried and unorganized...

Thanks!

Mark.
75 ABA/JH/MSnEDIS/LM-1 project
80 S
90 Audi Coupe Quattro - 10vt