To add to the thoughts. I just got them. They are solid! All my speakers are Revel and my NAD HP-50s (which were tested here) are EQed more or less to the Harman curve. Nothing about these makes them stick out from what I am used to. As it's impossible to AB at this point I can't tell you about minutiae differences tone-wise and that's fine! I don't see any disagreement with Amir's measurements. Ideally the measurements speak for themselves. Also, I think that they have pretty darn good "soundstage" for IEMs. There is separation of instruments/sounds. It's not that bad and I think the issue is overblown as the illusion of it--albeit more constricted--is still there. Sure they aren't like speakers or higher quality headphones but there is definitely a place of IEMs. (Now I have to compare them to my Etymonic ER2SEs--which I like.) I tried out the Malky79 EQ and I think that it makes them a bit smoother. It's not a dramatic difference but I think I will stick with it when I have the ability to EQ. Nonetheless it is great to have something super portable that does not require EQ. Would I use them over my NAD HP-50s? No. Upon a quick comparison the NADs sound feels a bit less strained --and, yes, the soundstage is wider; but then Amir thought the NADs were above average in that respect.
Importantly, they pass my bass test, which consists of the following:
Massive Attack - Angel: Representative of what I want bass to do well. If it can't make this sound good, I don't want it.
Laurie Anderson - My Right Eye: This is my test to hear bass quality. Before DSP, my speakers could not handle this track well as they would sound super bloaty. I think my NADs can handle this better, but the bass output is higher proportionally on the Zeros. This is not the fault of the latter as the NADs were EQ'ed. Still, these IEMs can handle it.
Billie Eilish - Bad Guy: Not really my music, but a great example of modern use of bass, which is so very different than music of the past. Here the bass is at the limits of what I like. Don't know if I'd want more bass than what these offer. That's a win in my book.
Critique:
I agree with others that the stem that goes into the canal may be too thick for people with smaller ears. I can see some women finding this uncomfortable.
And speaking of which, yeah, the whole Waifu thing is embarrassing. I hope the makers of these headphones see the sales potential that they have on their hands. Don't blow it! These should compete with the establishment such as JBL, Samsung, Apple, and AKG. Obviously, they are now distinguishing themselves with advanced tech such as noise reduction and EQ--rightly--but this is still an opportunity.
Case in point: I have an adult female friend that asked for headphone and IEM recommendations. I would certainly bring these up but I am not looking forward to having to embarrassingly explain the whole incel vibe of IEM culture.