I got these just after Xmas. I bought them because my current ones sufferend the one ear of death issue. Previously I had full size DJ monitor headphones. These are a little smaller than that but are bigger than Skullcandys.
The ear cup is comfortable for wearing for long periods and the noise cancellation is very very good. I only use mine for gaming but they could probably be used outside due to the noise cancellation.
The only issue I found is that the standard cable length is very short. They do include an extension cable but the extension is complete overkill and about 5x longer than the stanard cable so its one extreme to the other.
Also the bass is acceptable but isn't great. It performs best in mid-range and due to this they are great gaming headphones.
They do take some time to burn in though. At first they are very dull and flat sounding but after a week of use they will be at their best.
Definitely recommend. If you haven't heard of Denon before then basically they are a company that produce very high quality audio solutions, primarily surround sound amplifiers.