Today I go back to the same Sony Store as last time and listened to the Z1R again and did some comparison with my JVC FW10000. Both have the DMP-1Z as a source with the Z1R connect via 4.4 balanced and the 10K with 3.5 unbalanced.
Let start with soundstage. The 10k has larger soundstage with more out of your head depth while the Z1R is a bit more intimate due to it's more forward mid. Both sound amazingly open and are among the most open sounding iem I ever heard. The Z1R has better imagine capability with more holographic soundstage, instrument at the left and right side sound amazingly real and and has more body than that of the 10K. The 10k has better treble extension with more air up top while the Z1R is smoother while still retain amazing level of detail and life-like tone (probably one of my favourite part of the Z1R). The 10k is ever so slightly brighter than the Z1R with leaner mid (not thin). Not much impression about the bass this time unfortunately but there is nothing wrong with both lol.
As
@Mimouille had already reported, the mid of the Z1R sounds very slightly dry and brittle but I only found it to be apparent in some tracks. I have no idea if this is the final version but the unit look very new and has been station here for demo not more than 2 weeks ago. They also open pre-order at this shop.
As of right now I prefer both over my Solaris if anyone is curious.