Greeny, in a way you are right, it gives you a much fatter bottom end, generally not in a bad way either. however it can be bad if you didnt want that pickup to sound fat and punchy, but wanted it to sound more balanced, or more trebly
for example when i was using my gretsch filtertron, if i had the pickup close to the strings the tone was always like "back in black." However with the pickup slightly further down, i got a balanced highway to hell sound. Finally with it a fair ways down there, I got a "TNT/ A long way to the top if you wanna rock and roll" sound
NB; this is mainly my experiences for rhythm work for leads i found it was smoother with a closer pickup, and more... articulate when it was further away.