Joshua made a later comparison video against the Meze 109's that the Sennheisers had better timbre and vocal body. While the Meze 109's had better detail highlights and fun sound signature... etc etc

https://www.youtube.com/watch?v=LBlSV9ITMtk

For anyone reading this I highly recommend watching the full review.

Anyways, can't wait for a price drop for everyone looking into the S2's. Nothing like a headphone that becomes more accessible for everyone else and hearing good reviews on a headphone you've been enjoying for a long time :)

Also regarding EQ'ing the 660S's, I might give it another go, but basically the gist of it was to give the 660S the Oratory1990 treatment and then modifying the treble to sound more accurate. The Oratory1990 makes the 660S sound grainy and worse than the original sound. Halfway into listening the S2 as a reference I just sat there and got carried away with the music lol