Yesterday, I received Somic V4 and KZ ZS3. Here are my OOTB impressions.
Somic V4
Bass is amazing, good extension, a bit emphasized sometimes. Mids, as a vocals head, I approve. Clear and detailed, but imo XE800 is a bit more detailed. Treble is sparkly, detailed, crisp, and rarely sibilant. I'm really impressed. If I'd compare it against XE800, I'd say they are of different species and it all comes down to your preference. V4s are energetic, fun, and great for almost all genres, Vivos are analytical and great for bass-light genres like acoustic and orchestra.
KZ ZS3
Though I like the build quality, I wasn't that impressed. Bass is good but imo it lacks depth and texture. Mids sound unnatural at times, but pretty good nonetheless. Treble is sufficiently detailed. I'm more likely to listen to EDM with these, the ZS3s are dark (sound-wise and build-wise).
Just my 2 cents, these two IEMs still need some burnin'