Just got a pair today. Was considering Hifiman 500, but was going to wait until sometime next year. These were less than half the price, with 15 day trial, so after reading many a
"way above their price point" sort of reviews, I figured "why not?" Still researching for a headphone amp that I will run off my highend tube preamp in my hifi rig (Convergent Audio Technology (CAT) SL1 Signature MK III), right now using an Apogee Duet 2 that I bought for combination music recording/macbook pro semi-portable headphone amp duties. Will be nice when I get an amp to listen to vinyl (!), though I'm going to run the preamp into the Duet 2 for now so I can. Anyways, right now listening to 24/96 and cd WAV files via Songbird on the macbook pro. Have a pair of Ultrasone Proline (2500, I think, older model), Beyer DT770 Pro (250 ohm version), and a pair of Beyer DT250s that I use in my professional life as a location sound recordist for documentary, television and commercial video (originally bought the DT770 Pros to mix with as I was getting tired of years of using Sony 7906s, not realizing it was the more accurate DT250s I was supposed to by, so I got an extra set of headphones I didn't need).
I have been investigating orthos of late, esp. since I have electrostatic hybrid speakers (Innersound Eros MKIII), and have familiarity with planar transducer sound. I've auditioned Audeze and Hifman offerings at canjams, and had been considering LC2 or Hifman H500 (though in a different zingy dynamic way, the Sennheiser 800 also intrigued me). Anyways, got the modded Fostex headphones from Mr Speakers. The first few minutes was interesting: I expected to be knocked out and was not quite. Seemed a bit laid back, bass shy, etc. I reminded myself that these were planar headphones, and just as I got used to and came to like how electrostatic planar speakers reproduced music, I should approach these as a different animal than dynamic headphones. Also, I realized the phones may not be burned in, the duet 2 was not "warmed up", etc. Well, within 10 minutes I was settled into what these headphones would do. They are great, esp. for the price. Like what I like about a number of electrostatic and magnaplanar speakers: a sense that the music sounds detailed (but not in a hyped way, like some dynamic speakers and tweeters can be), but at the same time very natural and "real". Spacial cues are quite evident without being thrown in your face. Like the detailed yet strangely forgiving nature of some electrostats and planars, the high frequency info is there, but not hyped up or peaky. And midrange is clear and natural. Bass is very good, not the deepest yet tuneful and quick (these are not bass freaks rocker/hip hop headphones, but they still play rock, punk and metal fine). I goofed with high rez and CD level WAV files, a mix of stuff including John Coltrane, Talking Heads, Sleater Kinney, Black Sabbath (yes....), Air (10,000 KHZ superstar, great headphone album), Eric Dolphy, Queens of the Stoneage, Nick Drake, Pink Floyd, Wilco, 60s Rolling Stones, Miles Davis, Love, The Doors, Merzbow (extreme Japanese noise master, great for breaking in speakers and headphones), plus some audiophile goofy but nice sounding test tracks. These headphones were enjoyable with everything, with well recorded material they displayed all the strengths of the recording: spatial cues/soundstage, intimate details of vocal performances, etc. With bad recordings they showed off that they were bad/lesser recordings, but like with my home speakers, while you could tell it was poorly recorded, you could still sit back and enjoy the music (the fact that these headphones are slightly warmer than on the bright side helps with this a lot. Not the case with my Ultrasones, unpleasantly bright sounds are presented on those headphones as especially unpleasant bright sounds, making some poor recordings less pleasant to deal with).
I have a feeling these will not be going back, and even if in the future I find a more expensive pair of headphones that performs better enough for me to spring for, I would still keep these as backup or less expensive headphones I would travel with. But I don't feel a rush to get something else, just discovering these wonders. Next is a decent amp to run off my tube preamp at night to listen to vinyl while the wife sleeps. My guess is with these headphones is that I want to get something a bit robust, and that with the Apogee Duet 2 (and my ipod/AOL Audio amp portable combo) I'm not hearing 100% what these headphones can do. A good headphone amp will bring that to life.