Pros: OK build quality.
Cons: Overblown bass, compressed mids, clipped highs.
A buddy of mine found a pair of these at microcenter for $30 on a crazy close out deal. The retail for these is $250. I borrowed them from him to test them out and give them a review and all I can say is they weren't even worth the 30 bucks.
The first fundamental problem with these is they have an amplifier built in. That's great but it's not clean at all. You can hear the distortion it causes in the bass when you turn it on. You can also hear the bass rattle the plastic in the headphones on some tracks. The headphones have pass through but with the amplifier off the bass is gone completely, so in order to get these to sound anything like a headphone you have to have the amp on.
Completely overbearing and muddy. Distorted to an extreme in some situations by the amplifier.
The mids on these headphones seem crushed down. They don't flow throughout the full sound of the headphone and it sounds as if they are trying to condense them for the bass. You get bass where you should get mids on the bottom side and you get nothing on the top side.
The highs are rolled in to the mids at a fairly low frequency and are gone on top. There is nothing going on in the higher frequency ranges. They just cannot hit them. Acoustic guitar and voices suffer greatly from this and the clarity does as well.