I've been reading this thread for quite some time, but not really commenting. However, I have a quick question about the M100 on amping. I noticed that the M100 ships with a smartphone control cable, and also that headphones lose the smartphone control ability when amping. Does this mean that the M100 will be driven just fine without an amp out of my Sansa Clip Zip?
Correct. The M-100 sounds just fine out of my Rockboxed Clip Zip. It doesn't have the same bass punch as with a FiiO E7, but the difference is pretty small and it is still very acceptable for a portable device.