Nice review! May I also ask for a brief sound comparison with FiiO x5iii?

I would consider the FiiO x5iii to be analytically colder in sound. I do still like the x5iii, but mainly use my M3s and #2. I know some might consider the FiiO to be of a warmer sound, but not to me. It is pretty neutral and provides me with an almost "sterile"-type sound.