I can give you some thoughts on the Amiron vs the Fidelio x2. I pulled out the x2 just a couple of nights ago for a listen, I had not used them for at least 2 years.I used a well recorded prog-rock album for the listen. I will start off and say for the price the x2 is not bad at all. However the Amiron is the better headphone at least for my taste. The high-end on the x2 is a little more sharp not as smooth as the Amiron. The Amiron does have a treble peak, it does not seem harsh at all and not as zippy as the X2. The bottom end on the x2 is not as tight and maybe a touch wooly. The sound stage on the x2 is really good maybe a tad better than the Amiron. I find the mids on the x2 more recessed then the Amiron. Overall I believe the Amiron is the better headphone, it does come at a price though, $599 vs $275. If I was on a budget I could live with the x2. However I do not mind spending the extra money for the Amiron. Hope this helps a little.