Pros: Non-tiring yet engaging sound. Comfortable. Elegant design. No need for amping.
Cons: Detail and bass might not be to everyones' tastes.
Got these on a sale, and was very pleasantly surprised. Originally, I was looking for something that isolates well and does not sound tiring for use in the office, but ended up using them as my first choice HP (instead of Alessandro MS1, Porta Pro, KSC55).
I have been using them with uDac2, 2nd gen iPod nano, and Audigy 2 ZS. They are easily driven by any of these sources. Also, their low impedance does not seem to be a problem.
They sound engaging with almost anything without being tiresome or offensive, be it highly compressed mp3s of not-so-well mastered stuff to HD lossless audiophile recordings. On the other hand, the sound rather obviously lacks detail, and the quantity of bass might not satisfy everyone.
The design is elegant, and build quality solid. They come with a fair amount of accessories, yet I had to buy complys to fully enjoy them.