Someone left a pair of Monster DNAs in my career lab today, so I took the opportunity to pinch them for a while and do a mini review.
The build quality is fair. They look very good, and they feel good in your hands. They feel pretty solid. However, they fail in the mini details - the outside is prone to fingerprints, you can see seams in the headband construction if you look hard enough, and the folding / extending mechanism feels really cheap.
The inside of the headband is made of a nice rubber-ish material, and feels good on the head, as well as keeping its shape and uniformity when bending or extending the handband. However, the ear pads, which are a memory foam similar to what can be found on a V-MODA, are very uncomfortable and rest on the ears very poorly for an on-ear headphone. Only ten minutes in, I was feeling ear pain.
Isolation is decent but nothing to write home about.
These headphones are extremely efficient/sensitive and were probably purpose-built to play loud. On my Rockboxed Sansa Clip, the volume was at a high level at -20dB RMS.
The sound was surprisingly decent. No part of the frequency spectrum jumped out at me as offensive, and the headphones were pleasing to listen to. The detail level is fairly good, and the bass hits hard enough to be enjoyable without overwhelming the mids or treble. However, I have two major issues with the sound - for one, the tonality is terrible. These sound as though you're listening to speakers inside a wet paper box (I suspect due to a combination of boosted mids and treble dips). Secondly, there is zero soundstage to speak of. This was to be somewhat expected as these are closed on-ears, but it was still a disappointment.
My conclusion: These are probably pretty great for the average consumer, and they're certainly a fair deal better than the disaster that was Monster's previous similarly-priced on ear, the Beats Solo. However, I doubt that these are going to satisfy someone discerning enough to be on this board.