i'm familiar with the hd800 having heard it a number of times on different set-ups. i started my comparison with the hd800s and found it pleasant enough. it's still a bright sounding headphone tho. it also had ample bass. other than that, it didn't seem to differ too much from the hd800 from memory. that was until i switched to the hd800 and the differences between the two were more than subtle to my ears. the hd800 was even brighter and the bass was dialled down quite a bit. i didn't listen to it for long - it was just too fatiguing for me. so the new iteration's shift in tonal balance is welcome. that said, the hd800s seems to have lost some extension and air in the treble region compared to the hd800. whether that translates to a loss of ultimate resolution i don't know, but there did seem to be something missing and i don't think it was just glare.