Pros: Amazing sound clarity for the price.
Cons: Nothing big enough to mention.
These are the finest sounding headphones I've ever owned. I've owned Bose, Sennheiser, Audio Technica, Kilpsche and more and these new HD drivers DO sound noticeably cleaner then all. I know there are even better sounding headphones on the market but you'd literally have to spend double or even triple to top these. Also though they list for $260 you can totally find them for around $150-$200 if you shop around. Absolutely recommended.
Oh and by the way the MDR-7509 and the MDR-V900HD are the same specs the 900 is just the newer body style.