Received it, been testing all day using AIMP3 player @ WASAPI @ 48khz @ non-balanced mode with dark jazz, trip-hop, post black metal, many songs with lots of instruments, clean and harsh vocals: got spaciousness+lots of details in sound+warmth+clear vocals+soft kick drum, nothing drowned out or sounding harsh. Dunno by how much, it feels like all my neutral headphones got extended low end, fidelio x3 is not as neutral as with k5 pro ess, hd560 also, fidelio x2 sounds meaty in low end, warm, yet detailed. I don't see any problems with volume knob, and light around it is not annoying eyes, not sure what is everyone mad about it. Fiio driver v5.30 installed, no glitches, no pauses, everything is working smooth, i love all my favourite artists and bands via x3, x2, hd560s + k7. Enjoyed it in online competitive fps games too, x3 was good, but mainly stayed wtih hd560s + k7, splendid. I am already thinking to sell k5 pro ess, maybe it's placebo, and difference is smaller between the two, yet i am enjoying every minute with k7.