Feature:
Comes with a bag and a screw on adapter for 1/4" headphone jacks. Keeping it simple is key with me.
Quality:
The soft ear pads feel great, and they don't shred to pieces when they get a little wet from sweat. I can use them working out and not having to worry ruining them. I am not a big fan of needing to buy new sets of things yearly, especially when they cost over $100. I've had mine for a little over 6 years now, and they barely show any wear.
Desirability:
Comfortable and loud, enough said!
Sound:
SOunds much better than any other set of headphones I have ever used. That includes some of the cheaper Sennheiser's and anything by Koss, Stanton, and Gemeni. Great bass and clear highs. Never had any distortion come out of these badboys either.
Ease of Use:
Plug it in and go!
Overall:
I am about to buy a new set of these headphones. I figure that the life of these, for as much as I use them, to be right around 5 years. Mine have gone above and beyond the expectations that I had for them when I bought them. As long as Sony continues to make them I will buy them. There is not another model for me. They have worked for me cutting the grass, working out, in the airport and on planes, and going from my bedroom to friends houses for DJing fun. In my opinion it is the only Sony product I have owned that is this great.