Pros: Fantastic comfort, great sound, incredibly easy to drive, very very light.
Cons: Not the strongest feeling headphones (super light), Sound terrible out of the box, Very long burn in period (36+ hours).
The S400 and S500 are incredible quality bargain headphones, but these even at several times the cost are more refined and more worthy in every way. If these cost $120 i would still recommend them, they have made that much of a impact.
Out of the box they sound pretty bloody bad, everything was muffled and the bass sounded like it was coming through a wall. That's just the way these JVC's seem to ship, after 48 hours though these are a whole other beast, one worthy of your time and money, at least as a travel pair.