I also liked the fact that the XC does not sound like your typical closed phone: tight bass, no cavernous / nasal sound and pretty open staging.
That said, I found both X and XC too bright for my tastes, a bit shrill/harsh with some rock recordings I sampled (all from the vendors rigs). I wished I could compare against the previous lcds but looks like there was no space left in the suicases for those.
I think those looking for an exciting sound might really like the audeze. I see myself more attracted by the fostex planar prototype, the voicing and comfort being much more to my taste. I also listened to the mad dogs (actually the 3D printed cans) through the mjolnir but again found it too forward in the mid/highs and preferred the fostex voicing.
It was thus surprsing for me to find out that most of the recent planar offerings are going for quite detailed / bright sound signature. I have plenty of upper register detail with my 009 so not in the market, but I can imagine these new generations of planar phones finding a large audience in the market.