I purchased these after doing some research on others experiences with them. I have personally only tried a few other headphones such as Bose noise cancelling and Bose AE2, Dr. dre beats, and a bunch of the sennheiser phones in higher price ranges. I can say I am extremely happy with the choice I made, and would not trade the M50s for any of the others I tried. I listen mostly to classical music, and they sound excellent right out of the box. As others have said, the music is much more nuanced, but of course more so on tracks with higher bit rates. I wanted to push them more so I put on some rap and R&B music. Wow oh wow oh wow!! The way the bass reverberates around your skull is incredible.
These provide spectacular value, considering the quality you get is equivalent to, or better, than phones in significantly higher price ranges. I would recommend them.