I found the SR-007 to be a very interesting headphone. My impressions come from owning the SR-007 with the SRM-007T, as well as an extended audition of eric343's KGSS.

The SR-007 is very easy to listen to. It's soundstaging is excellent, and it does very well with vocals especially. The transparency is excellent. The bass extends quite deep, however the impact is sorely lacking. The SR-007 does not do particularly well with rock music. It also has what I would consider to be a "fat" midrange. That is, there is a frequency hump in the lower mids / upper bass. This gives the SR-007 a slightly dynamic sound. The detail on the SR-007 is good, but not what I would consider to be outstanding. They do not convey "presence" very well. That is, when listening to piano, one will hear incredible detail in each note. However, the room acoustics, and sound of the piano's wood is not conveyed convincingly, if at all. This was also the case with the human voice.

if I didn't hear the HE90, this would probably be one of the best headphones I've heard so far. the sound slightly emphasizes the bass frequencies but it isn't overpowering and is a nice balance with the rest of the spectrum. it is fast, detailed, and sounds superb.

being electrostatic headphones, the sound changes as the headphone charges up. my impressions were done after the SR-007 was continuously powered and charged for at least a week. the amplifier used is a HeadAmp Blue Hawaii.