By the way, $240 for a pair of used D600 would be a pretty similar price to a pair of used M100. I know you haven't had the M100s for very long, but which do you think is better? I think the Craigster likes the M100 better, if I'm not mistaken.
The more I listen to the M-100, the more I love it. Great for my portable rig, better than I expected.
Cavalli said it best, I don't know which is better cause they all have a small niche use to me and I'm happy to have this problem of too many good phones. A good problem to go have. The D-600 is better at comfort, M-100 better for portable.