The fabric earcups on these guys do breathe better than the P5's leather earcups, though they'll still get your ears a little steamy on warmer days. You get a decent amount of passive noise-cancellation, though over-the-ear models will do an even better job muffling sounds from the outside world.
It's worth noting that the P3s have a straight plug rather than an L-shaped plug. The common wisdom is that L-shaped plugs are preferable. That said, straight plugs tend to offer better compatibility with a wider variety of smartphone cases, which can sometimes leave the headphone jack fairly recessed.
As for performance, the P3s sound very good and like the P5s have detailed, well-balanced sound and good, tight bass. If you're looking for a headphone that really accentuates the low end, this isn't it. These are pleasant-sounding headphones designed to work well with a wide variety of music. They impress on their own, but my view of them changed a bit once I compared them with the step-up P5s. The P5s just sound a bit more detailed, open, and refined. In other words, that extra $100 you pay for the P5s does get you better sound. It's not a huge difference, but it's there.
I also compared these with the
In the end, the P3 is a strikingly designed headphone that sounds very good. I can't say this is a great deal at $200, but it's about what you should expect to pay for a headphone that features this level of industrial design, sound quality, and features. Yes, you can find headphones that sound better in this price range (the
If you're trying to decide between this model and the more expensive P5, that's a tough choice. Because this model is lighter, it's a bit more suited to mobile use, though I have seen plenty of people walking around New York with P5s. Of course at the time I saw them, they didn't didn't have a choice between the P5 and P3. Now that they have the choice, I have a feeling some would opt for the P3. Overall, it may not be as good as the P5, but in certain ways it's better. That's why it's a tough call.
Editors' note (June 13, 2014): The rating on this product has been updated (lowered from 4 to 3.5 stars) to reflect changes in the competitive marketplace.