I’ve been meaning to comment on this for a while, as I’d imagine most people here weren’t so happy with my L3 review. Myself and some others have criticized the L3,
but I do think the mixed impressions might also have a lot to do with unit variation. Antdroid himself has experienced this first-hand more than anyone, as he's graphed three or four separate L3s (his first one had a different tuning on each side). All of them have had different frequency responses to varying degrees. And to this effect, he definitely prefers some iterations more than the others with the CIEM being the best.
So my problem with the L3 lies not strictly with it's tuning/technical performance, but more so the unit variance that seems to be present. It seems like there's some good apples and some bad apples out there.
Like it or not, just going off the data at hand, there's clearly something up. And as a prospective buyer myself of the CIEM, it feels like a lottery.
Furthermore, I generally understand technicalities and the FR to be mutually exclusive. But I've also noticed that most people don't seem to be affected by the timbre issues with only a few outliers like myself, Banbeu, and another reviewer friend mentioning it. And just to make sure I wasn't going crazy, I confirmed with the kind person who lent me their L3. It'd be pretty tough to not notice IMHO, so maybe there's some correlation with the unit variation.
If these issues didn't exist, then I think a lot of my problems with the L3's technical chops would be mostly attenuated. Or I'd at least find it decent for the price and a safe recommendation; some of the versions also have more treble extension which was another of my gripes.