I received my ZSXs today (along with my midnight blue V90s, what a happy day! ). I plugged them into a balanced cable, I'll skip the stock one altogether. Started to listen on the R5 and I actually had to dial the bass down a bit on the MSEB from where it was! The soundstage on these is outstanding - wide and deep, stretching out in all directions.
The comfort is substantially better than I'd expected, they're not as big as I thought, and the shell is nicely contured. But the sound - oh my goodness. Guitars and cymbals dance around in the soundfield. Bass and mids are impactful and full of body. Highs sparkle but aren't metallic or fatiguing. I'm not sure if I can lay down in them without too much ear pressure - they aren't small, but hey - I can prop my head up on some pillows.