I cannot compare it to the Sennheise pair I initially wanted to buy, since I decided to go for ATH after having read many reviews. And I agree with the positive ones. The sound quality is excellent. I tried them with my laptop, compact stereo, clavinova and smart-phone. They deliver a much better sound in the complete spectrum, using different kinds of music. It is noteworthy that using a not optimally ripped Sony recording of Glenn Gould (AAC audio file, 128 kbps, 44100kHz), I could start hearing his humming more clearly than with any other set of headphones or in-ear phones I had used before.
The long cable is for my purposes a major plus. The extra protection of the cable at the junction point with a metallic cover as well.
I used them in an office environment and the sound isolation was really good in both directions.
Although I was not very sure about the design (which looked a little old fashioned to me initially), when they arrived they really made me think otherwise, because they give a "higher quality" visual impression.