Pros: Well crafted, detailed and realistic timbre
As the subjective sound quality of the SR-009 has been extensively discussed in the other reviews, I will focus on my objective experiences. Whenever I purchase new high-end products, I always choose to run a blind test consisting of the model in question alongside other high-end headphones. This time, the comparison counterparts included the LCD-3, HD800, HD650 and Orpheus.
My subjective impressions always tend to take a similar route: there exists a very strong correlation between the price tag and the sound quality that I perceive. It was no different this time. Therefore, I performed the blind test on ten participants who are all fellow classical musicians in a blindfolded setting (with the volume matched etc).
The results this time were indeterminate. However, the HD800 came last followed by the Orpheus. After the blindfolds were removed, the Orpheus was unanimously agreed as having the best sound quality (the Orpheus does look rather magnificent). The Stax was chosen to have the best sound quality by three people.
This kind of test demonstrates that all these high end headphones do not have such a huge disparity in sound quality as made out by other subjective reviews. Therefore, I am always slightly let down by products with such a steep price tag as the Stax. Evidently it is not as steep as the Orpheus, however, for this money, I believe it is more worthwhile buying a pair of speakers.
I believe it is also important to stress that the superlatives associated with this headphone should be taken with a grain of salt, in fact several pounds would suffice. I do not think that the SR-009 sounds bad. On the contrary, I believe it sounds fantastic (I had very similar experiences to Currawong's review). However, as this test has demonstrated, it does not outperform other high end counterparts with noticeable significance (this is especially noteworthy as the other test headphones except for the Orpheus are considerably cheaper than the Stax).
Hence all in all, I believe that the SR-009 is an outstanding piece of gear, but by no means the King of headphones.