I had reviewed the B&W C-5 headphones earlier, and mentioned I was disappointed in the overpowering bass; not what I was expecting from Bowers & Wilkins. I mentioned that I had ordered the P-5's, and was hoping that it wouldn't have the same problem. I am ecstatic to report that they don't.
Clear, faithful sound stage, vocal reproduction, an easy to use case and the ability to switch between iPod-compatible (controls for volume and ability to advance / rewind from the lanyard) and standard audio cables make this a winner! Highly, highly recommended! On top of that, they're extremely comfortable, feel well made and look like they're going to last. Its in the same league or superior to the Sennheiser RS-180's in terms of comfort. Being closed though, you get no leakage which is good for the other people in the room :-)
I've partnered them with a FiiO E7 headphone amplifier, with the EQ set to bass boost +1, and its amazing how neat the sound is. Highly recommended combination.