I'm beginning to miss the emotional connection, excitement, passion, intensity, (whatever a good word for it would be that I can't seem to grasp) that I used to get from my music collection. The X2 never gives me goosebumps. The X2 never fatigues me either.
I just need a distinctly opposing headphone in terms of signature. HD600 was even less lively and more boring. Passive as opposed to active listening maybe? I never feel the want/need to sing along with my music on an HD600. They put me to sleep like music isn't even being played. The X2 isn't that bad, but it isn't as engaging as I'd like it to be all the time. This is all personal preference of course.
I love my X2 for different reasons and they work a lot better for games and VoiP than some of my other headphones did. If money, comfort, size, fit, weight, etc. weren't factors... I'd lean towards an Audeze LCD-3F, Hifiman HE-560 or HE-6 (lmao, no chance). Due to those same factors, I'd probably buy a Beyerdynamic T1 or T90 (T90 might have too much of a peak/spike); HE-560 would pass everything except monetary restrictions I think. Hard to say without having them in front of me.
I put on my DT990/600 one last time before shipping them out to their buyer. Goosebumps; hair standing on end. I wish they weren't so v-shaped and artificial sounding. The hot/harsh treble (sibilance is nearly gone) didn't even bother me in the slightest on my new Mini-i Pro + V100 combo.
All of this might be slightly off-topic for the X2 thread, but I feel it's relevant enough to bother posting.