(cross posted from the X1 thread)
I was doing some comparisons late last night with Colorfly C3 and X1.
C3 sounds slightly brighter, more airy, you can feel a good presence of air from the stage above the upper mid-range. it edges out in soundstage width and can come across as slightly thinner sounding and slightly coloured, euphoric.
Bass response on C3 while good in quality isn't as powerful (due to C3 suffering small amount of low end roll-off in It's design) But X1 sounds tighter in refinement and a little higher in resolution, the mid-range is thicker with more meat to it's bones which makes C3 sound a little underdeveloped.
If we're talking about detail I think C3 does have an edge which mostly pushes out in the upper-mids, take female vocals for example will have more extension to them, they'll reach out further, but take males vocals or a singer reaching down low X1 has great heft to the music that digs in and grabs your attention, it's smoother and still quite close in detail, more even response rather than
slightly tilted upper-mids.
Area's like separation C3 has X1 beaten but not by much as one would think. In a nut shell they're rather different signatures that can live side by side, I would lean to say it really depends what you want from your music and which headphone / IEM you're using.
Does one player pull away from the other quite notably? No, not really, (which is surprising) but depending on the pairing will matter more so. Take for example my Fidue A83, they need some air to their presentation and extra space, due to my personal preference a slightly brighter DAP works well so the winner is Colorfly C3. Then take Altone200 which needs a slightly warmer source to shine, X1 wins as the better pairing for that earphone.
If you start adding features, usability and settings into the mix X1 completely slaughters the C3 in that department.
People would know I'm a big fan of C3, have been for a long time. But X1 is surprising me more and more as time goes on.
Just some thoughts I've gathered along the way.