Well, the official line is that the MX4 was conceived with professional studio users in mind, you know, it is meant for those who need to sit at a console for hours and hours of mixing, critical listening, and all that great stuff, although, it is understood that some regular users may be find its attributes attractive.. If I remember correctly, the same used to said about the LCD-X, at some point before the MX4 came out, so I personally took the MX4, at least, initially to be a new and improved LCD-X. When I personally got to hear the MX4, I did like it a lot, but I also found the sound to be too close to that of my LCD-X when used on my rigs, whereas I was going for something a little more different and unique-sounding than that... That is why I parted ways with the MX4 and went for 4, which has got me closer to where I wanted to go with the purchase, and then some...
Still I do not see anyone who does not have the X experiencing the same problem I had with the MX4... Hell knowing this hobby, there might even be many owners of LCD-X whose experiences of the MX4 would be different from mine, so different ears, different systems, and system synergies too should be considered in all these conversations. I know you have probably heard this a zillion times on this site, but if you would allow me one more indulgence, then I would suggest that you let your own ears be your guide...
Yes, the search can be frustrating and confusing sometimes... I know the folks at Audeze always mean well, and are consummate professionals... And yet, like all such professionals, sometimes their marketing strategies can leave one scratching one's head. I had such a moment when I read the following on the Audeze MX4 page:
"A perfect combination of the LCD-X and LCD-4, the LCD-MX4 has the easy-to-drive diaphragm and voice coil of the LCD-X combined with the extreme magnetic force of the LCD-4. It features a different soundstage presentation than the LCD-X or LCD-4 to help simulate a room’s sound."
Okay, I don't know about you but that made me want to go like "huh"!!??? rather than say "Eureka!!!," especially where they're talking about soundstage representation and simulating a room's sound
I have the X and the 4, and I spent about one month and a little more auditioning the MX4 before getting the 4, and I still can't wrap my head around

how that statement is supposed to tell us how the MX4 actually sounds...
When all is said and done, though,I still like what I heard of the MX4, and I adore Audeze products in general, so I shall cut them some slack here, and quit the light ribbing