See, I think of refinement as lack of jaggedness. For instance, the GR07's treble is more laid back and warmer than the Etymotic HF5's. However the Ety's treble is more linear, without all the dips and peaks of the 07. I don't really think it's a matter of warmth or richness.
Difference of opinion. I said more than warmth. I also stated detailed. I heard the HF5. It's very detailed, but I wouldn't call it refined. Just about every refined IEM I've heard has a touch of warmth to go along with the extreme details and richness. And yes, I will agree there tends to be some smoothness in the sound.