I got one of the early LCD-2 Fazors in early 2014. It remains one of my fave cans after about 20 years of experience with headphones starting with the HD-580 in the 90s and many others in between. What I like most about the LCD-2F is the smooth natural sound in the mids and bass, and treble that is fast yet not bright. This matches perfectly to the natural acoustic music that makes up most of my listening.
The LCD-2F has a slight recess from about 2 to 9 kHz. This recess is smooth and linear so it doesn't change the voicing of voices or natural instruments, but it does make it sound warmer than the real thing. I perfected the sound with a parametric EQ, +3 dB at 4500 Hz, Q=0.67. This is just enough to counteract the recess back to a neutral level without changing the overall character of the sound.
Then the LCD-X came out and I've always been curious about it. Similar to the LCD-2 Fazor, yet a bit faster with more neutral frequency response. That sounds like perfection to me. Audeze had a B-stock sale so I finally pulled the trigger on it. I'll give it a listen, compare without any filters, and report back.