The M100 is genre specific, which is why I didn't opt for it personally... if I wanted a pair of phones for dance music and hip hop I'd look into them but as my tastes a broad and range from EDM to Hip Hop, Jazz to World music I felt the Classic offered a broader distinction. Had these on my head for a trip from London to Amsterdam by coach and ferry all the way and felt no need to take them off, the Pro's pushed down on my ears slightly so I had problems with those when I had them although on hindsight I wish I'd let them burn in some more before sending them back for the Classic as although they weren't as comfortable they were wearable on the road whereas the Classic just tips over the 'too big' line in the sand. As my trip was to Amsterdam what music listening I did enjoy with them was under the influence of hash cake so the awesomeness may have been tinted in that regard but watching movies through a Fiio DAC and Tablet it did very well and often caught me by surprise in what it revealed in the music and narration there regardless of the low resolution.
The failing of these headphones is the cusions as you can't take them off... the 4m long cable is actually quite useful for me and you can use any cable with it as long as the jack is long enough, they fold... I sat on them by accident on the coach to The Netherlands and the cups went into a flat position, they come with a card warning that they're not to be put into this position at all so I was shocked to notice that they could but its obviously a failsafe as they clicked back into a normal position and I couldn't put them back into the position again without undue stress to the joint.
Very open and spacious sounding, when there's no music playing they let a lot of sound in which on hindsight is why I didn't mind having them on when my tablet battery died on me... yet to give them a go on a train in a large city, Amsterdam not counting as a large city .lol.