If you are overwhelmed by the choices of headphones available in the $300 price range, are looking for something to use at home as well as on the go and care about quality sound while also appreciating deep, powerful, tight bass, these are simply the best choice available. The M-100 sounds great with every type of music and really shines with popular and electronic music. In additional to excellent bass, vocals, instruments and highs are detailed and smooth. These don't offer the over-the-top muddy sound of some "rapper cans". The sound is pure, clean and fun. Imaging is great- sound can be perceived coming from all around you which is typically more prevalent in open-back headphones. Even though they are full size headphones, they have an innovative folding design and come with a surprisingly small form-fitting case as well as some nice accessories like the share play cable.
At first, I thought these headphones were not as comfortable as some others due to slightly smaller earcups in comparison, but these have loosened up and have a nice secure fit for active use. I can listen for several hours without discomfort. I can also enjoy these sitting in a chair or exercising.
The M-100 goes as loud as I need with my Iphone 4, so you don't need an amp. However, as with most headphones, they can benefit from an amp and can handle higher volumes as well as boosted bass. I own the white version and they look fantastic- a modern, industrial work of art.
I have literally auditioned dozens of headphones in every price range and the M-100 is the best, most enjoyable headphone to my ears that I have heard under
$1,000. If I sound like an M-100 fanboy, it's because they are that good and have earned the praise.