Well, my IM02 came in th mail today. Will update with impressions as I listen.
Edit: first impression is that they're fairly forward, which is good. Bass is a tad mid centric, but it seems adequate overall. I didn't realize how small they'd be though.
EDIT: Ok, here are my impressions thus far:
TL;DR The IM02 are better than any other IEM I've tried and are a very welcome portable compliment to my HE-4
Eartips used: Comply M tips that came with the IEMs. All of the Silicon tips are trash IMO.
Bass: Very clear, deep reaching overall. Definitely less presence than my FS Atrio M5, but that's to be expected since those are dubbed the 'Sub Bass Kings.' The quantity is definitely acceptable and, honestly, preferred in most situations and the quality is very high as well. Bass is definitely not one-notey.
Mids: Not forward, like a good IEM should. TBH, I didn't notice the mids, which is probably a really good thing. They were there, not recessed but also not too prevalent, which took away some warmth from the IEM but in a good way. These definitely aren't a warm, relaxed, veiled IEM, but they definitely aren't a Grado either.
Treble: Very nice. Vocals are very clear and the treble overall sparkles. I don't think I've heard any sibilance at all so far, so props to AT. Cymbals can be a bit too forward in some recordings, but not enough so to be distracting.
Really, this IEM in some ways reminds me of my HE-4, just with less resolution and openness. They aren't quite as forward as the HE-4, but they certainly aren't veiled either.
The IM02 are definitely here to stay, and were exactly what I was looking for, as far as I can tell right now. Thanks all for your additional suggestions, even though I kinda went against the grain and grabbed the IM02 anyway.