I just wonder why no electrostatic headphones on the list? Is it you haven’t heard any?
I will agree on your first 2 excellent headphones but the 660S’s I just don’t care for much. Really like the the Clears as well and only heard the 1990’s once and didn’t dislike them as I remember. Have the 6XX’s and Sundara’s and would also put them close together as they do what they do very well and at a good price. The LCD-2 closed backs I didn’t care for much but think the LCD-X is pretty good and would place them around the Arya’s as the first time I heard them I really liked them but after hearing them again still liked them but there was something that just seamed a bit off but could have been me and listening to too many headphone’s that day.
I will say I do agree with many of your impressions on many of these and I own 30+ headphones and have heard many many more. Just my subjective opinion. And to your oops the new Utopia in my opinion better than the original also a excellent headphone.