Since I purchased the headphones a few weeks ago and warmed them up with pink noise for around two days, we will infer that they have become more comfortable to wear. The basses have a good amount of elasticity, and the frequency response appears to be even; I did not detect any peaks and valleys at any of the frequencies. Sound quality is excellent across the board. A headache was experienced initially as a result of an accurate replication of low frequencies; however, after one day, the headache was no longer present (before that there were open g4me 360). These are pulled at volume 37 by my player, which is a Cowon x9 (out of 40). The noise is coming from above. My initial assumption was that it would not pull because the impedance was 150 ohms, yet it actually swallowed without causing any discomfort. (For comparison, audio-technica ath-m50 with its 32 ohm produces the same loudness at 34). So, even without an amplifier, you can use it as a portable device that has a suitable amount of output voltage. We were successful in listening to both ONE and ZERO while we were in the store. It was impossible for me to choose between these two pairs of headphones. The simple fact that ZEROs have decent bass makes them sound far better than ONEs. It is the main justification behind it. Yeah, because your ears are closed in ZERO, you will experience some degree of sweating. While we are seated in these chairs, we will not be able to hear anything that is going on in the flat. Yet, each of these things ruins the otherwise wonderful sound. The decision has already been reached. I don't regret it at all =)