Dave, interesting comparisons! And they align well with what I wrote. The mechanical aspect ie. stiffer vertical suspension seems to me still a very important factor.
Recently Shibata tips resurrected, interestingly at the top of the ladder. I principally assumed tha a vdH / Gyger Type I stylus or a MR stylus were "better than Shibata", that's the way they were introduced in the eighties. Maybe... it was already good vdH marketing - or the re-inroduction of Shibata is? However, from what I read about the new top AT MM cartridges, I somehow trust that the Shibata excel in optimizing the musical detail vs. amusical artefacts ratio.
The resurgence of conical styli, with the original SPU or DL 103 "cult" contains some arguments pro conical styli. Ie. a suggested geometrically much more complex pinching effect / movement of the "sharper" modern styli, including MR or Shibata. This would lead to spurious vertical movement as artefacts (more with these sharper styli than with conical styli), and is a claimed reason for the more relaxed "pro-music" way of musical tracing of these very traditional (and superb) cartridges.
Extending this line of thoughts... could mean that the "real" advantage of these sharper styli would stand out considerably more with a "real" mono cartridge like a Miyajima Zero, because the spurious vertical movements would not be decoded, or far less. And the lack of out-of-phase, vertical stereo signals would eliminate a source of intermodulation on top of these spurious movements.