[sneaglebob]

They look exactly the same and appear to have similarly sized drivers but whats supposed to be better?

 

[GL1TCH3D]

Driver size isn't the only thing that affects quality >.>
To answer your question, the M100 is supposed to be better.

 

[gelocks]

The M100s is "voiced" differently, so it is NOT a "bass-head" phone. Treble extends higher than the V-MODA M80s, mids are a bit recessed, bass slam and quantity is there but not at the levels of the XP. Construction is mostly similar with the exception of the "hinges" which are new.
 
At this point, it will be preference which one you pick. If you are a bass lover first and foremost, the LPs will probably suit you better.
 
 
Thanks.