Koetsu cartridges. They must be something special.

I heard about Kiseki. Dutch designer and they are made in Japan, right ?

Kiseki of old is not the current day Kiseki. 

I have not heard one, but some say thar Etsuro Urushi cartridges are similar.  The bad news is that they are quite expensive.

Re magnets, bizarrely, they do have a sound. If you listen to some Strat pickups with ceramic magnets vis a  vis those with alnicos, you'll hear it pretty quickly. And its not just down to field strength.

Some of the best midrange you’ll ever hear. Defined, full, smooth, exciting, they open up a whole canvas of sound when compared to other cartridges. This, balanced with thunderous bass and ever so delicate and defined treble make them a joy to listen to for hours requiring no effort from the listener. That’s what makes them special. Just my opinion.