I use this headphone for several years. What struck me most when I tried it, it's accuracy and linearity. I have tried many headphones, and the MDR7506 is by far the clearest and most accurate.
on the other hand, it's a headphone pro: someone that is not a professional sound (so accustomed to listening to a plate) will find that these headphones sound medium. The stereo headphones great public always have a hollow in the medium to make a big sound with bass and treble surraccentués, to the detriment of the accuracy and linearity. So a professional point of view, it is great.
Note that bandwidth is very broad, and it is very very punchy. And even if it is a bit expensive, it more accurately than the MDR7509 and premium Beyer, both become even greater.

In addition, it is easily transportable and each piece can be changed without specialized smallest batch sizes. It is true that when one is pro, it's a big advantage.

So I really nickel and referrer this choice without hesitation.