Do you still have the dnas ? How did they stack up to the m100s? I noe its on ears vs over ears but still. That was another option for me too, i saw it at christmas for 100$ which is unheard of for a "monster" headphone ( well aside from the ntunes). But monsters all plastic plus the hinges as any foldable headphones except the m100s look shaky vmodas warranties was too sweet, so i waited.
The DNAs have been passed down to my nephew, and he's extremely tough on his electronics and somehow they keep on ticking. I wouldn't worry about durability with those. As for the sound, the M100s are probably a bit better overall. A much wider soundstage is the biggest advantage. Both are extremely efficient tho and don't need an amp. I felt the M80 needed a small one to bring out it's best (especially the low end).