Well, I like the Sony-Kimber cable a lot since it adds liquidity and a silky quality to the mids and vocals in particular (I own one). It also adds some welcome bloom and plumpness to images.
I'd be curious about the Axios cable, but it's a lot of money and I haven't read much at all here about how it sounds.
One person I think said it was great, but that's the only report I can recall seeing. Any more impressions would be great. Thanks.
As to the earlier questions, I feel the Z1R is a league above the TH900, which I sold after a few years of ownership. The TH900 was nice but would sometimes go overboard with pounding upper bass or whistling highs.
There was just something unnerving and fatiguing about the sound of the Fostex, like it would hit too hard without warning and lose control.
And the mids and vocals did not have the fine texture of the Z1R.
If you like the Z1R and want another to add to your headphone menagerie, I suggest the Hifiman HE1000v2.
It has more definition and speed than the Sony, and is more airy, but is just about (almost) as non-fatiguing and is also tolerant of lesser recordings like the Sony.
But the Hifiman does not have that profound speaker-like punch and spaciousness of the Sony. The Z1R seems to create its own big thrilling environment like no other headphone.
The HEKv2 and the Z1R are my current favorites and I own both.
('never heard a Utopia, Elear, Pioneer SEM1, or any ZMF headphone, just for the record.)