Well, while listening to a dozen different pieces of music chosen for their properties intrinsic qualities (see list at end of post), I did not notice any particular irregularity. Maybe, and I say "maybe" there he has a little more velocity and accuracy in relation to 2.20L0.
Note that I used a Shure SRH-940 very revealing with whom I prefer the sound of 2.18 to 2.20 fw. With the SRH-940, the 2.20 appear mid-centric with a bump on the lower midrange and the trebles, light attenuation in the high medium and tenser bass but less extended than the 2.18. And your version did not diverge in that direction. Also, the 2.20 (L0 and Wx) has a very nice separation of instruments and an incredible definition and a very balanced sound. But the sound stage is narrower than the 2.18... For now, awaiting to change my headphones, I return to 2.18L0,which the DX90 is more relaxing and musical. I repeat, this is only my impression using precisely this headphones.
[Playlist :
"The lost song 1&2" by Anathema, "Holy Breath" by Dhafer Youssef", Clark : "Snowbird", Agnes Obel : "Fuel to Fire", "Entanglement" by Michael Price, Roberta Flack : "Killing me Softly whith his song", Miles Davis : "Shhh Peaceful", "Passage" by Chris Spheeris & Paul Voudouris, "O King of Heaven" by Valentin Silvestrov (Kiev Chamber..), "Become Ocean" by John Adams (Seatle Sympho. - Ludovic Morlot), and some passage of Lucia di Lammermoor by Donizetti (Sutherland, Pavaroti - Bonynge) ][and only Lossless and HD files...]