The new owner of the London Decca name has told me he hopes to restart production of the Reference and to offer a new version. He had suggested they would be available in August of this year.
It is cheating, in a way, to include Deccas in this discussion, being tip-sensing cartridges with just a couple of millimeters of the end of the armature effectively acting as the cantilever. All the other moving iron designs (eg Grado, SS, Nagaoka) are quite different, though I would be fascinated to learn how the mass of stylus/cantilever/moving iron compares to the stylus/cantilever/magnet or stylus/cantilever/coils of more common MM and MC designs. Is the cantilever assembly of a Hyperion lighter than that of a high end MC cartridge? I don't know, but I'd be interested to find out.