In the guitar world, the lower resistance the pickup, the more "mellow" it's sound (especially combined with the softer magnets).
The higher the pickup resistance, the more signal was sent to the preamp. More signal going to the preamp meant that a more distorted sound could be achieved at lower gain levels (though this didn't stop guitarists wanting more gain). I always found that the more gain used, the harsher the distortion anyway, and the signal tended to "mush" sooner, loosing loads of string definition.
Bass-wise, I would say that low-mid-ish resistance pickups would be best (circa 7-10k Ohms?), enough to get a decent signal into the preamp, but not enough to distort it. The last thing you'd want is to loose string definition and loads of "mush" with a bass.
Just my opinion.