My opinions are based on listening to FLAC (mostly) and MP3 files sourced by an ASUS Xonar DX on a desktop computer. I used mpd to play music directly through ALSA in Linux.
I was really hoping when I purchased the SMH-1000 that Senal had managed to not only parrot Sony's design but also replicate the sound of the MDR-V6/MDR-7506. I really missed (and still do) the enthusiastic midrange and sparkling highs. Hearing each frequency equally "forward" in presentation was a delight and made it easy to distinguish various instruments. The SMH-1000 however, is much more conservative and I suspect that's what most listeners will prefer.
Bass punches do not sound much deeper but they do seem to linger a bit longer, leaving an impression of greater impact without muddying the sound. The midrange is definitely more recessed, and the highs are more rolled off. With these changes, songs don't seem to have the same energy as they did with my MDR-V6. How then is it that I consider the SMH-1000 the superior headphone?
The characteristics that I described of the SMH-1000 remarkably (to me at least) result in a sound that is more interesting. An effect of distance between various instruments has been achieved that is not so well accomplished with the "full-steam ahead!" approach of the Sonys. That's not to say that I haven't heard something similar before. In particular, I'm somewhat reminded of the Creative Aurvana Live in the manner of separation of instruments. However, not only do instruments seem to have space apart -- but I can almost perceive the emptiness between them; the void has weight. This gives what I can best describe as an ethereal feeling to some recordings.
Conclusion
I imagine that the MDR-V6/MDR-7506 having nearly equal representation of sound at the lows, mids and highs, incidentally resulting in music that (to my ears) sounds exciting, is desirable in a studio setting. http://www.innerfidelity.com/images/SonyMDRV6.pdf
When it comes to just music listening though, I think most audiophiles will find the SMH-1000 superior due to what I would call a greater sense of depth. Considering its conveniently detachable cables and shamelessly hijacked design and folding functionality, it's probably the best studio-style headphone for around $100. Personally, I still often hear certain intricate songs and really wish (even now) that I owned a pair of MDR-V6s to savor every detail, even if I can only stand to listen for 30 minutes.
I leave you with some marketing jargon from the back of the SMH-1000 box