Is there a dealer in or near your area that carrie’s both? There’s no substitute for auditioning headphones with your own ears.
Another person to ask would be @Resolve since he had (has?) both and previously had the opportunity to directly compare them.
I have them both and would be happy to weigh in but would first like to know if you are going to be using EQ?
Blessings,
-J
The real answer is if you can use a fully open back headphone in your listening area(s) … if not then you only have one choice and that would be the LCD-XC … if you can use an open back headphone then the LCD-X will have its advantages
Yup, that about sums it up. 
-J
I remember that Karthick at Audeze has told me before that they prefer linear phase and that is the default possibly for the Roon plugin version. I guess they added it to Reveal+ as an option as well now
Definitely X if you’re okay with open back.
It looks like the default mode for the Audeze presets in Roon is “Zero Latency”.
The other option (at least right now) is “Linear”, which adds about 1.5 seconds of latency.
I prefer Linear Phase thus far, changes to the FR notwithstanding. It sounds like Audeze’s Reveal+ definitely boosted the lower bass response and also the upper mids on the LCD-X 2021 preset, and I am liking what I’m hearing. I still prefer the changes to the FR using my own PEQ through Peace EQ, but that doesn’t change the phase as far as I know, which is kind of a bummer.
I imagine there’s a way to add a linear phase filter to Equalizer APO, although maybe not in the newer revisions? You used to be able to add the Audeze Reveal plugin to it, but it no longer works.
LCD-X 2021 EQ Revision (08-30-2022)
For more punch and slam
Hear new nuances in tracks that you’ve listened to hundreds of times before and get your money’s worth by breathing new life into your LCD-X 2021 with this update requested EQ.
At first glance this EQ may look bass heavy, and it is, but if you listen with open interest you’ll find layering and texture within the never muddy warmth. The mids are not encroached upon too much and the highs are crystal clear and liquid smooth with just the right amount of sparkle.
This EQ started with @oratory1990’s most excellent Harman target compensated graph and grew and evolved from there over the past 9 months for its final birth here.
80Hz is exaggerated in order to target bass drums and make them slam and cut through the mix. The dip before 40.2 Hz is there to give sub,sub bass some punch to bass guitars.
The frequencies often responsible for the “clarity” & “magic” from 3.7 to 4.3 kHz are highlighted and balanced with the high frequencies bordering hearing capability at around 14 kHz and above to enhance the detail oriented aspects of your music coming close to, but without being, overly “shouty” for the majority of mixes.
Pre Amp: -15.35 (Be sure to enter this value to avoid clipping)
Band 1: Freq 40.2 Gain 5.59 Q 0.69 Filter Low Shelf
Band 2: Freq 40.2 Gain 1.2 Q 4 Filter Low Shelf
Band 3: Freq 80 Gain 6.1 Q 1.7 Filter Peak
Band 4: Freq 90 Gain 8.4 Q 0.65 Filter Low Shelf
Band 5: Freq 112 Gain 2.7 Q 1.41 Filter Peak
Band 6: Freq 200 Gain -3.45 Q 2.41 Filter Peak
Band 7: Freq 300 Gain 3.53 Q 1.2 Filter Peak
Band 8: Freq 575 Gain 2 Q 3 Filter Peak
Band 9: Freq 785 Gain -2.5 Q 2.2 Filter Peak
Band 10: Freq 1235 Gain -1 Q 2.4 Filter High Shelf
Band 11: Freq 1500 Gain 8.1 Q 0.71 Filter High Shelf
Band 12: Freq 1910 Gain 1.3 Q 5 Filter Peak
Band 13: Freq 2700 Gain -3.55 Q 2 Filter Peak
Band 14: Freq 3750 Gain 4.15 Q 1.4 Filter Peak
Band 15: Freq 5780 Gain -4.95 Q 4.1 Filter Peak
Band 16: Freq 7350 Gain -2.15 Q 7 Filter Peak
Band 17: Freq 10000 Gain -0.65 Q 0.8 Filter Peak
Band 18: Freq 12500 Gain 1.45 Q 2 Filter High Shelf
Band 19: Freq 19000 Gain 0.65 Q 0.7 Filter Peak
To increase or decrease sub-bass, adjust gain to Band 4 to taste.
To increase or decrease high-mid range “shoutiness”, adjust Band 14 to taste.
To increase or decrease treble, adjust gain to Band 17 to taste.
To increase or decrease upper treble/sparkle/air, adjust gain to Band 18 to taste.
Here’s two original tracks of mine to try this profile out with that I mastered with the LCD-X 2021 that really pushes these cans to do things previously not thought possible by me:
Jonne Haven - “Big Bad World”
Jonne Haven - "Used Cars On Mars)
No, but seriously, hype aside this is a pretty good EQ that will eliminate global hunger and achieve world peace.
Blessings,
-J
You could try this, seeing as it’s a lot less EQ filters and might sound pretty similar. Obviously adjust the two bass low shelves to your preference.
You have to take into account unit variation, of course, but it should look something like this:
It’s not my cup of tea, but others might enjoy it. Happy listening!
Have come and gone and come back to @JonneHaven’s EQ. IMHO it’s the best I’ve tried- better than Oratory 1990 or the Audeze LCD-X 2021 Roon Pre-set.
One extra practical issue I haven’t read anywhere else. I found that the clamping force of the X’s had become quite weak, and I could not get a good seal at all. I found that by tightening the Phillip’s head screw at the bottom of the strap slider, at the point where the earcups attach to the headband, this can be adjusted, and whatever clamping force desired can be adjusted. See photo.
Yup, that’s the advantage of the dual hinge frame Audeze used before going with the single support yoke arms on the LCD-5 and MM-500 where it’s more limiting in what can be done.
Thanks for the validation, man! Encourages me to keep making it better. Happy listening! 
On the aside, I don’t understand how that screw controls clamp force. Intuitively it seems that it would tighten and loosen the swivel? I’m not understanding the physics but I want to in case I lose clamp force with time.
Blessings,
-J
PS - I’m curious do you use my EQ “as is” or do you adjust the Bands I mentioned as adjustable? Or do you adjust the EQ otherwise as you personally like?
I use it as is… no adjustment is needed for me, it is now the only way I listen to my LCD-X 2021. Good Job!
I am looking forward to checking this headphone out very soon!
It was in my top three under $1200 headphones for a few months. I just don’t crave them very often so they have slid into fourth place having been displaced by Monoprice AMT. Still, I appreciate the quality build and truly exceptional Audeze customer service.
I look forward to your impressions!
It’s really good to know you use the EQ “as is”. Helps me to hear the experience of others. Thanks!
Blessings,
-J
Audeze MM-500 Announced June 3rd, 2022 - #60 by MRHifiReviews posted my video comparisons over on the MM-500 thread! Here it is also.
Really love the fine grained one.
However, looks like my FR graph looks a bit different from most.
I really like it, but am looking to make mine a bit bassier (not sure if that dip on the low end is typical or not). Would anyone be able to suggest where I should add a bass shelf (or where to put a peak) to get overall the same sound, just with more powerful bass to really make tracks fun?
