I went from the AKG K701 to the HD800. Let me start by saying there was a drastic difference, but not without any flaws. I quicky realized that the HD800 sounded flat and fatiguing. I sold me old amp and DAC and bought the Sennheiser HDVA 600 and RME ADI-2 as well as the XLR cable. I can tell you that the sound at times is magical but, I still I can't listen for longer periods of time because of ear pain even with EQ.

In my opinion it is a headphone that has stood the test of time and is still considered reference. It still holds its own against the very best headphones out today (at least in soundstage). I say go for it! Perhaps, you won't find them as fatiguing and for the price you won't find any other headphone that can compete especially at a used price. Good luck! 😊