I'll try to make a parallel point to explain my perspective. While trying to listen to a few different setups in preparation for an upcoming meet, I listened to HD800S and HD650. I'm, of course, opting to go with the HD800S because I find it to be a better headphone. However, I do not find the HD800S to be a universally better headphone versus the HD650. The HD800S is cleaner, less grainy, and clearer in its presentation - in particular through the mids to highs. It has bass, and probably dives deeper into the bass versus the HD650. However, there is, in my opinion, just a nice balance from lows to highs, and in height, width, depth of the presentation through the HD650. I feel the HD800S adds more, but does not add quite as linearly as does the HD650. The HD800S is more for the highs, I feel.
In contrast, a few weekends ago I was able to listen to LCD2 and both generations of the LCD-X. If it matters, a friend brought his 2014 (2013 original version), while mine is a 2017 (2016 updated version). Though these sounded different from each other, they were still both, in my opinion, significantly better than the LCD-2. And unlike the HD800S/HD650, I felt the LCD-X (both versions) were in every way possible better than the LCD-2. The LCD-2 is quite the bargain, and still has the Audeze house sound. But the LCD-X simply extends in both directions, highs and lows, and fills in details across the spectrum, while not losing any sense of balance (i.e. the highs don't dominate, the lows don't dominate). So I agree with the original post that the LCD-X is a complete upgrade versus the LCD-2.
In contrast, a few weekends ago I was able to listen to LCD2 and both generations of the LCD-X. If it matters, a friend brought his 2014 (2013 original version), while mine is a 2017 (2016 updated version). Though these sounded different from each other, they were still both, in my opinion, significantly better than the LCD-2. And unlike the HD800S/HD650, I felt the LCD-X (both versions) were in every way possible better than the LCD-2. The LCD-2 is quite the bargain, and still has the Audeze house sound. But the LCD-X simply extends in both directions, highs and lows, and fills in details across the spectrum, while not losing any sense of balance (i.e. the highs don't dominate, the lows don't dominate). So I agree with the original post that the LCD-X is a complete upgrade versus the LCD-2.