Pros: Overall sound, look, easy to drive, good noise isolation
Cons: difficult sweet spot for best sound, needs lot of break in, cable quality, maybe a little bit more detailed on top?
FIRST: don't believe any reviewer who listen to the P5 only few hours or a couple of days, they need minimum 60 hours of break in to start sounding decent, at 100h they sound ok. At first they're so closed in like listenin' with a big and heavy curtain in front of your head, no detail in any frequency, no dynamic, just ugly sound with boomy bass and not even punchy. I was shocked the first time I hear them, "who could ever buy this crap?" was my first impression.
SECOND: pjoliver182 mod http://www.head-fi.org/t/576341/b-w-p5-modifications is essential and the cheapest and easiest upgrade to gain bass detail, dynamic and better definition in any freq. Just add a little isolation material (also cotton will work for testing differences) in the upper part inside the ear pad. I've done this review with this essential mod, before I was very close to return the P5. Thank you again pjoliver182!
THIRD: They're very sensitive to ear pads position, move pads up/down/front/rear to get best results for your head. You need to experiment a bit to get best bass extension and articulation, focus, dynamics or to retrieve more ambience and soundstade depth.
The target for me was to select a portable HP without the need of a stand alone dedicated headphone amp, so they must be not too big and sound ok with an iPod, smartphone or a notebook.
Any difficult to drive or low sensivity HP is ruled out.
Overall rating is based on this needs.
I've used for testing: iPhone 4, iPod Classic 160Gb, Blackberry Bold 9700, Dell Precision M6600 Notebook with IDT hd audio codec and JRiver MC16 with WASAPI Event style in Windows 7 64bit, Linn Majik Kontrol or Naim Supernait+HC2 built in headphone amps with Linn Majik Ds or Naim CD5XS+FCX2 as sources. Lots of HD tracks 24 bit downloads tested. I think some of the listed equipment is good enough to judge overall quality and differences of HPs I targeted.
I've tried a lot of different types of HP so to have a general reference, I still have the following for testing purposes and to add some direct comparisons:
Sennheiser CX300 (in-ear)
Sennheiser HD535 (low sensivity)
Grado GR10 (in-ear)
Grado SR125i (low sensivity)
Monster Beats Solo HD
Overall the CX300 (best buy in ear for Whathifi) presentation is the most similar to the P5, a lower level P5 if you will: less detail and dynamic, less articulated and punchy bass, less separation and ambience, less armonics and less stable at high volumes.
Grado's are much more dry in sound, if you like them you'll hate the P5 tube like sounds. At first Grado's seems to pull out more details but now I think they loose some body in the sounds which for me is another part of the details and they've a mid/high freq bump not so comfortable to use with common headphone sockets, don't know how things goes with dedicated amps, but I'm not interested as stated before.
Monster Solo HD is much less detailed and too much boomy and exagerated bass to be serious.
Value 4 stars: they're not cheap nor they're too much expensive, very good VFM given the quality of construction and overall sound. At nearly 300 Euro they've more VFM than Monster Solo HD at 200 Euro for example.
Design 5 stars: I love the design, colors and materials used. I rate this parameter very high and I'm proud to show them around to anyone. Very appropriate even for older guys like me at 44 who don't like to emulate rappers and prefer a classic but modern look. Beautiful bag.
Confort 3,5 stars: at first they seems very confortable, but during long listening they start to pressure your ears too much. For over the ear they could be improved at least half a point, I'll give five stars only to around ear and light HP. Also it's not so easy to find again the sweet spot position if you change the distance of the earpads for storing them in the dedicated bag, it's so narrow and that detract a little to confort of use. Last cons: If it's hot they could make your ear hotter. Isolation confort is very good even if it's still possible to do better.
Audio Quality 4,5 stars (with pjoliver182 mod, without mod 4 stars, see SECOND point above): The sound is on the warm side with very good timbre fidelity, good dynamic and detail but not the champ here especially if you don't do the mod. I can't believe some reviewers stated they could be spitty or aggressive. I wish a little bit more HF detail and extension for perfection, that's why not a 5 star rating. Maybe a better cable could do the job but it's very difficult to upgrade it given the type of implementation: 2,5mm jack and even smaller than normal to fit it inside the ear pad, 3,5mm on the amp side.
With break in AND mod AND correct sweet spot, the critical bass is excellent, powerful enough to give justice to any kind of music, controlled and detailed enough to not miss anything in that department.
Midrange is british, its stronger feature for the one like me who appreciate it that way. It's detailed and full of body, not sterile. Voice M or F, saxs and pianos are very enjoyable. Some sounds even ambient sounds or voices from people speaking in live performances like jazz sessions seems so real sometimes I pull off the P5 to ask my wife if she was speaking to me or look around if there's someone moving in my room...
Overall what is so easy to love about the P5 is the coherent sound, it's not coherent in a neutral cold way, it's coherent in a tube like fashion. Any frequency is colored in the same way, so there is not a disjointed rappresentation of the music, you don't hear a super detailed HF and at the same time a boomy undetailed bass for example, nor you need to listen to only one kind of music or just a few tracks which are recorded optimally for your headphone. Any recording and genere could be enjoyed in a satisfactory way because even if colored any parameter is in good condition. Think about giving 7, 8 or 9/10 to various aspects of the music and sound instead of a 4, 7 or 10/10. The latter is less enjoyable in the long run even if some aspects are better. So you don't have the best HF extension but it's good enough to enjoy details and the meaning of the music and interpeter. The Prat factor is very high, the midrange british and tube like, the sensation of lots of harmonics add to the musical presentation. You can feel the body of instruments even if they could be more detailed, Grado's Hps on the contrary seems to loose some weight to instruments and voices even if they're perceived more detailed. Drums are not so fast like Grado's but are much more punchy and more full. Pianos the same, not so detailed nor so thin, more round and more decays and harmonics. I like much more now this type of presentation. I think Grado's are colored too, just in another way. Just b/c you could enjoy lots of different recordings or generes not means the P5 color the music in such a way all sound the same, not at all. You could hear great differences between recordings and that's why you are always happy to check the sound of the new HD file you've just downloaded.
Another strong feature is the volume you could push these little babies, more you pump the volume more details and dynamic you gain without fatigue and without congestion or lost of control. So in the end you start thinking, are they really less detailed or I just need a stronger amp to achieve better results? On the contrary with Grado's you think, maybe a dedicated tube amp could be the right choice...
Overall an excellent 4,5 stars: they could be more confortable, less picky sweet spot, maybe more detailed, maybe...