Broke out both FLC 8S and Delta just now, volume matching by ear.
Jammed the first two songs off Fleetwood Mac's Rumours album. First is more energetic with make vocals. Second is languid, with a good bass line and female vocals.
FLC 8S was in my preferred Max Sub-bass, Med Bass, Med Mids, Med Highs config. Delta was with gunmetal filter.
If you're looking for a technically capable IEM you can fine-tune to your liking, FLC 8S is it. It's not going to reach Delta levels of bassiness, so if that's your gig move on and don't look back. It will however give you very natural and appropriate bass response, non-recessed mids, more detail, and much improved separation and soundstage.
No disrespect to Trinity. Delta certainly is fun but definitely sounds non-technical and a bit claustrophobic in comparison. I look forward to hearing what Trinity accomplished with the Phantom Bass, which *should* be a more technical IEM.