Unbalanced Pickups; specifically: bar magnet vs pole pieces

In the catalogs, you see the Unbalanced Coil Pickups and one coil has a bar, the other has pole pieces. But I have a Dynasty where both sides are a bar magnet.
What difference does that make?

I also have a line on a transition/possible UK Spectrum Series II that has the same thing. I think it is original, but I'm trying to figure out if it is unique enough to pursue...

If you bend a string you won't get any drop in the magnetic field on a bar.

But youll get more crosstalk between strings