Pros: Good in passive mode, great in active, and decent noice canceling
Cons: My ears get warm, and a bit too big and heavy for laying on my back.
I bought these headphones a little over a week ago, and thought I should post my impressions. I work in a small office, and sit close to my boss, who is constantly on the phone, so I wanted a noice-canceling big headphone for home and for the office. I first listened to these a year ago and fell in love with the sound, but my wallet didn't allow the purchase, and now I own them, and am very happy with them.
Previously I owned the K701's, but sold them because the headband hurt my scalp, and I've been using in-ear phones since. I mostly liked the sound in the K701; the bass was very correct, but sometimes not that fun, and the highs were incredibly unforgiving. The PSB's are more balanced in my view, and have a bit more oomph, especially with the built in amp on. The noice canceling works well in the office, but does change the sound slightly, I can't put my finger on what happens, but it is not as good as with just the amplification on. Either having a stack of batteries handy or a charger seems to be needed, but I think this is a better solution than a built in charger.