The first thing you'll notice with these headphones is their build quality and their aesthetics. They ooze premium quality like the interior of a BMW or Mercedes Benz. With their leather wrapped ear pieces and the industrial looking metal on the outside of the ear pieces with Bowers & Wilkins engraved in, these are just plain sexy.
Moving on to noise isolation, B&W boasts the fact that the P5 are closed back with sealed earpads. With that being said, during my testing, I agree they surely do seal out almost all exterior sound. What is mention worthy though is that there IS some sound that will leak out. I'm not saying it matters for the listener (:D) but it may be a concern for those around you, especially if you listen to these in an office environment.
By design, the P5 headphones are pretty comfortable to wear and won't squeeze your cranium too much to the point of discomfort. After an extended period of wear, say an hour or more, I feel they get to be a little snug on my ears. It's not a deal squasher, but it helps to take a break from listening for a bit. Other than that, they are very pleasant to wear not to mention the plush pad on the top band that rests on top of the listeners head.
Sound Quality - this is what you guys truly care about, right? The B&W P5 are more true neutral and warm but they are no slacker in the bass department. Listening to Daft Punk's Random Access Memories, you can definitely hear the warm sound of the P5's. They prove to be a little light on the treble at regular volume levels but the treble begins to emerge at higher volumes. In my opinion, I prefer a warmer headphone like this versus something that is so heavy on treble that it gives you a headache. Warm headphones allow a much more pleasant and comfortable listening experience.
In the packaging, you will find the P5 along with a replaceable headphone cable (with no 3 button iPod controls), a 1/4" headphong plug and an uber premium carrying bag for your precious new headphones. Retail cost is $299.99, available with free shipping on Amazon here.