I am indeed a proud ZMF Eikon owner and a massive fan of them.
While the Eikons cost about as much as the Radiances, they are a completely different animal- if anything, they have more in common with the Shures (but with more detail and sub-bass to die for) and the Focal Stellias. However, the 300 Ohm impedance of the Eikons require an amp that can power them properly, such as a Violectric V200/280/281 or 202/others from their new lineup. There are also Beyer amps (A2/200) that apparently work well with ZMFs, as well as a Cayin SS amp that ZMF sells as well.
The best amps for the ZMF dynamic headphones, though, are tube amps (OTL models in particular). At least to my ears…
Based on that, I’d not mentioned the Eikons- but if you have the right amp, they will IMHO beat out the Shures and the Radiance by a large margin.
Did I mention I am a fan? **