TO be honest sir you might want to play with the setting so it suits your playing style. If you have the pickup too close you risk getting a fuzzy sound. Depending on what you're looking to play is really how you'll define how far they should be from the strings.
My bass is has about a quarter inch space between the pickups and the strings. Perhaps just a bit less. The closer to the strings the more "muddy" the sound might be. It's really personal preference. But you just screw in one side closer than the other to optimize the high/low depending on what you want to sound like.
I don't know for sure but I would assume Les Claypool plays with just regular settings and a slightly looser set of low strings (meaning heavier) while the highs are taunt and more precise. Could be wrong on that though.
A lot of the accents you'll hear in people's music has a lot less to do with pickups and more to do with playing style and tuning.
Also if you move the pickups closer to, or further from the neck you're going to get a different tone, but that's kind of the point of pickups in the first place I guess.
Also though, if your pickups are too close to the strings they'll cause tuning problems because the magnets are going to have an effect on the way the string vibrates.