More images can be found here:
http://zazenmatsuri.imgur.com/ex600/#Re8dX
I really do believe that the 600's reflect the absolute best bang for the buck at the moment that I've heard (I haven't heard the GR-07 yet). They deliver sound quality far above their asking price. I'd originally have given this honor to phones like the RE262, Radius DDM or the HJE900 at the $150 mark, but the 600s eclipses them all in areas of sound (not by miles or anything because these three offer superb audio quality, but they are technically better than all three) and build quality (which are kind of iffy on the DDM and RE262). Even the almighty SM3 looks and feels like a toy next to the 600s, which boast aluminum and detachable cables which is a huge plus as phones WILL eventually short out.
Had I never heard the SM3s these phones would really take it for me. Tonality, dynamic range, placement/imaging, soundstage, balance, are all top notch. Where do they lose out to the SM3s? They just don't engage me in the same way from song to song as the SM3s. This has a lot to do with the fact that the SM3s probably have the best midrange of any phone I've heard to date. The timbre of vocals and instruments just sound natural and realistic in a way that the Ex600 can't always get across (although they do come very close), and the forward midrange of the SM3s, while initially in your face, really brings forth a level of intimacy (especially in regards to vocals) that the Ex600s can't convey due to their wide soundstage. By the same token, the 600s large soundstage can be quite engrossing on some songs which just sound huge in a way that the SM3 can't always approach. In terms of bass, since both phones are quite comparable in terms of quality, I feel like the quantity of bass delivered by the SM3 is just right. The 600s can't deliver a driving bassline or drum beats with the same authority as the SM3, but its bass is exceptionally well controlled and textured. The 600s are quite fast, so this quality lends weight and punch to attack transients, which really reminds me of the RE262, which, while light in bass impact, doesn't sound thin because of it. Decay is similarly excellent, coupled with the excellent dynamic range, piano and stringed instruments possess great detail, nuance and realism. The 600s have a lot of treble energy which means that hi hats and cymbals have a lot of sizzle, and guitars leap out of the mix, but all of this can occasionally be strident and fatiguing in a way that never bothers me on the SM3.
If there's a phone that the 600s remind me of, it's probably the Sony SA5k, these are almost like a mini SA5k. The thing is, if I had never heard the SM3, what seem like shortcomings really wouldn't jump out at me, and these would likely be my favorite phones because they really are quite outstanding, and because of that, these get a pretty effortless recommendation from me. If you want top tier sound without shelling out $300, these phones at $130-150 (!) should
really be on your list for consideration.