MFD pickups. What's the difference?

[Ach]

Could someone explain to me please, what is so special in MFD pickups? Ability to "lift" polepieces up and down?

How do they compare to traditional pickups, in sound they provide and in technology they used?

PS: I found a patent number, but understood nothing.
PAT 4220069

Thank you.

[badboy1984]

Are you talking about the G&L pickups?

To me i think those pickups have very hot input and sound really really loud compare to the normal MM pickups. More aggressive sound to me. And also they can adjust each pole piece for personal preference.