One thing I've never managed to reconcile is the correlation between resolution and harshness. There's a case to be made that an IEM's technical ability can reveal a track's shortcomings. I've heard errors in fading (or pop-ins) and automation on some tracks (of mine and others) that were revealed to me by more detailed IEMs. As I mentioned on my ODIN review, that IEM's spatial capabilities will cause compressed tracks to sound small and mushed-in, and allow dynamic ones to feel vast and open. When it comes to harshness, though, I've never come across on IEM that's made a track sound sharp or fatiguing, simply because of how resolving it is. It always has to do with treble (or higher-higher-midrange) tuning; a tonal matter, rather than a technical one.
A more revealing IEM will, in my experience, always make a poorer track sound underwhelming - 'kinda like, "Oh, is that all there is to it?" - rather than discover some new, repulsive facet of it that'll make you shiver and wince. When I listen to a track whose flaw is that it's been significantly compressed, I shouldn't hear compression, but then harshness also, right?
I must stress that none of this is directed at the EVO. Again, I haven't heard it. I'm just trying to question the concept in general, which I've been hearing for years now with no strong justifications for it. The only reason I can think of for its existence in the first place goes back to the reference = bright propaganda I discussed on another thread some time ago. There was an idea back then that resolution and reference were closely linked to brightness, because pushing the treble was the main route brands were taking to achieve detail. So, when people found that their resolving, reference headphones were causing tracks to sound too bright or harsh, they'd blame it on the tracks, thus the birth of harshness = "distortion" or "flaw" in the track.
In reality, though, I don't believe there is such a thing, unless it's egregious and can be heard on any IEM or headphone, of course. To me, tracks are just like headphones and IEMs themselves. They come in all shapes and sizes, and they each have their own colourations. No engineer will mix and master the same, just like no IEM maker will tune the same. Inevitably, there will be times when the colour of the in-ear and the colour of the track just doesn't mesh well, and the fault is on neither party. Sometimes, things simply don't mix. That's life. So, rather than go through the rigour of finding which of the two is to blame, I reckon it's best to just find the one that works for you and move on.