Pros: Audio quality
Cons: Very thick cable makes it awkward to carry around
I first encountered these headphones in a superstore Germany. After listening in the shop I was blown away, the quality of the sound is fantastic!
When I got back home I tried out loads of different headphones but ended up ordering the Denons. In my opinion the Closed Denons are better than other open headphones (such as the Sennheiser HD650 which is what I almost went for) which i compared it to.
The sound quality is incredible; you'll be able to hear parts in music that you never even heard before.
2 notes of caution, first the cord is very long and thick which makes it difficult to carry round (I had to wrap them with tape). Secondly if you use MP3s you will now be able to tell the difference between lower and higher quality encoding and will want to reimport most of your music collection!!
That aside, I give these a big thumbs up and recommend them heartily!!