I don't think the usual tracks I use to evaluate IEMs are badly recorded (except maybe the metal ones; which, to be fair, are usually the ones that show me the most glaring issues of an IEM).
I tend to go more towards edgier stuff, so that my "boundaries" for producing are put in place.
This is more or less what I consider perfect in the lows, vocals are super nicely placed and held in place by the 3kHz area, they already sort of went too hot on the EW300. There's also the limit on the highs for me, anymore hats and hi-perc and you're overdoing it, but it's close to a perfect track. Master is gorgeous, although clipped AF (youtube won't show you that, but the engineer used the cheap trick to make it feel louder of letting transients through).
This one is like the flipside of Aquemini, almost too much bass (but not quite), hats are gone (any less and the drums are off), vocals and synths have the whole higher range. Simgot also crapped out but not like the first track. Bass was overwhelming, and Kendrick was sibilant. This isn't right, he is sitting at the very edge, but not over. The Hexas sort of lack the "bam" I got on my Audeze or my monitors, but nothing is "wrong", so I take it as it is, especially the hooks which sound perfect. Verses are too soft with Hexas, but that's not "wrong."
The next one is close to what I consider a perfect track, nothing is off, nothing is too close to the edge. I get the track as it is with Hexas, just delightful. You're probably gonna get blasted by claps and baby-screams on the vocals, maybe buried under bass
The Seed is the upper range of higher drums, of edge on the vocals, and of a "hot" mix and master, I cannot listen to "phrenology" for too long, but it isn't wrong. On the Hexas I get pretty much what I've gotten all my life everywhere else, on the Simgot the track was unbearable for me, overcooked and highs over-blasting everywhere
And once again, the opposite of that track, Erikah Badu and Glasper almost going way too soft and too much bass, but not quite.
And another "perfect" but everything on the limit. The track had too much bass, piercing highs, and too sharp vocals on the Simgot. This track exposes room problems when I am visiting other studios, it's the razor's edge for me. Almost over-compressed, but not quite, almost too much high-perc, almost too much 3kHz on vocals, almost too punchy bass. Edgy and perfect. Hexas are dancing with it.
And the low-end limit together with sharpest highs and honkiest vocals, but 2.1 billion play, the track is obviously perfect as the limit of what is doable. Hexas just eat it, Simgot gave me a headache...
Make sure to turn up the volume and keep loudness constant, youtube messes greatly with the loudness of masters that go too much past -13 LUFS (pretty much every good modern master...).