Zyx mistracking issue

The thread is two years old, so unless the OP is not using vinyl since he started the thread, one must assume he has either moved on or solved his problem.  But he is describing the performance of a cartridge he bought used in 2012.  Which means it is more than 9 years old as of now, and neither he nor we know how it might have been treated before he purchased it. One cannot seriously diagnose and treat a problem like this on the internet.

Grace F9 is much better with genuine US-14 stylus, this is next generation of styli for F14 (fully compatible with F9). 

The goal of US-14 is MicroLine (ML) stylus tip. 
Sometimes it's hrad to understand what type of stylus Grace used, but when ML stamped on the box it's for MicroLine. Here is mine. 

ZYX is very expensive cartridge and useless whet the stylus is worn, waste of money. I do not regret I stopped using them (Airy III and Premium 4D). 

Life is much easier with MM cartridges. 

I pursued my investigation and finally bought a new AT-OC9ii fully compatible with my Zeta arm. It tracks absolutely flawlessly! I optimized the asimuth adjustment; you can read about my experience (in french) in a short report. http://info.usherbrooke.ca/jpdussault/Audio/Azimuth.pdfIn summary, I experimented with five cartridges, the Zyx, Grace F9e, a Shinon Saphic, a DV23RS and the AT-OC9. All but the AT have close to 800-1000 hours of usage. The Zyx is the worst tracker, the AT the best and the DV-23 a close second best despite its ~1000 hours of play and some 35 years old...

@analoghaven I don't succeed in using my mini microscope to photograph a still picture of a stylus, so I can't imagine viewing a moving one tracking a record!

My only experience with Zyx is 2 out of 3 purchased brand new had production faults. Wouldn't touch one wth a 40 foot barge pole even though I did like the Omega very much, when it was built properly.

On my french forum a lot of people have got problems with zyx. I have been told that on German forum some people were not satisfied with zyx cartridge too.
I have bought a Benz LPS after the zyx experience.