Pros: Sound, Looks, Build, Comfort, Design.
Cons: None... the carry case is a little bulky.
(I've been using it exclusively on my ipod classic + PA2V2 portable amp)
This headphone is a genre master.
Sound: Very clear full sound with a natural timbre.
The bass extension is superb - it goes deep; ALL THE WAY deep, without ever intruding on the rest of the sound.
The mid-range is liquid smooth and full. Vocals don't have any nasal quality like some other closed-back headphones.
The treble is never fatiguing but always there, crystal clear. I really like the slightly soft treble presentation on these headphones - it really makes these super-easy-listening cans.
Comfort is flawless. I have small ears and these are the most comfortable headphones I've ever owned.
Build is seemingly flawless, no corners have been cut here. Even the plastic shells are slightly pearlescent in appearance and feel very solid. The cable seems thin at first, but the past few months have proved it's rugged nature.
Design is absolutely brilliant. I have seen very few headphones with aesthetics this good.
Paid 300 euros for these in land of Sennheiser. Worth every cent.
They are the BEST closed back portable headphones I have ever heard. They have an excellent natural timbre, and clear presentation that excels in the outdoors, on-the-go.
EDIT - Even after the slew of new portable headphone releases in the past year, I'm still convinced these are the best. (if your ears are small enough).