Yeah, Etymotics are quite good at hitting the neutral target, although one should take the different HRTFs of people into account. For some, they're the epitome of neutral; for others, less so.

Maybe just my purist preferences playing around here, but I don't think that flat necessarily sounds soulless like that, although definitely a bit boring. For me, flat means tight bass in quite meagre doses, unexciting but natural mids, and a somewhat cold but not harsh treble.

To be fair, I don't like DF either, because I don't think DF is neutral for mastered tracks, maybe for recorded tracks at most. For mastered stuff, something like IEF neutral is closer to flat for me.

To be a bit more accurate: he asked a few hundred listeners, some trained, some untrained, to select their preferred sound, and he tweaked the curve accordingly. So the Harman curve isn't a neutral curve, it's a preference curve. Not flat.