Maybe this is preliminary, maybe I am rushing, ... these headphones are not worth it for me.
Comparing them to $120 Bose IEMs ..... Shure 535, Westone W4 and HiFi RE600 are not 4 times better than Bose IEM .... nor are they 3 or 2 times better.
Westone sounds too weak. Reminds me of Grados SR225 .... lots of treble, little bass, I tried to get used to the sound but ... those are not made for smooth jazz or classic .... seems like they are more for rock, heavy music ...
Shure 535 ... nice, nice fit, nice sound, not $400 nice, at least for me.
HiFiMan RE600 ... some things better than the other two and some other music Shure is better.
Bottom line .... not worth for me to spend 3-4 times as much as my current Bose IEMs cost.
I also compared these to my Open HD598 over ear headphones .... with no surprise those beat all of the IEMs for me. Much, much bigger sound-stage, just enough bass .... no $400 IEMs for me.
P.S.
One guy on this forum once said that once you upgrade from those cheap $20 headbuds to something like even Iphones $30 IEMs, that's where you'll see the biggest sound difference. Difference between a $100 and $400 IEMs .... not that big compared to the price.