Thanks for the answer,
in fact I own both M-80 and M-100. At first M-100 listen, I was instantly positively shocked by the bass quality and quantity but didn't like the evident midrange recession and the harshness of the low treble. I decided to give them some time and I used them for 3 months then switched back to M-80. I listen primarly to modern rock / alternative and some pop, Muse, Radiohead,... As of today I think M-80 do everything better apart from subbass. In comparison mids on the M-80 are very detailed and airy, M-100 mid bass is very recessed while the mid to high transition is quite fatiguing. Also the highs on M-80 are quite natural even if recessed. On M-100 low treble are boosted while the highest octave is more recessed than M-80, making them sounding unnatural and fatiguing to my ears. I asked you about verza and M-100 to see if verza addresses the shortcomings of M-100 from my point of view (I don't pretend to be an audiophile but a casual listener who likes good sound).