http://www.villex.com/prtb.html
The big advantage of the Villex pickups over Lane Poor Jazz-style pickups (which also sound good, by the way) is that the Villex pickups work better in a passive-only configuration, due to the higher output level. Even if you don't use the midrange control (or the optional PRTB) you'll still get a louder signal from your bass to your amp (or pre-amp).
Additionally, I think the Villex pickups present a more wide-band and cleaner signal than the Lane Poor Jazz-style pickups, which have a more narrow aperture.
On the other hand, the Lane Poor pickups (wide aperture) do have a bit more "sweetness" in the treble details. Perhaps they output more of the frequencies above 5KHz, which is why the overtones and harmonics seem to have a bit more treble detail, despite the lower volume.