Ask me again in a week. Once I get my SA6 delivered, all I will be listening to are those three.
EDIT: I guess I can add a little about what I will be listening for. These are not impressions, more like reasons why I found the graph of these IEMs intriguing enough to warrant the purchase. So, I'll be explaining what I'm hoping for in these comparisons, not what I've heard.
While I love the Moondrop S8 for its insane detail and separation, it's got a small scoop in the upper bass/lower mids that ends up making some music sound bass light and note weight generally thin. Unless the music has a fair amount of sub-bass, then the S8 can veer in the other direction and sound too bassy, yet weirdly still thin. In other words, the bass has a bit of a coherence issue to my ears. Incidentally, this is why I skipped over the ThieAudio Clairvoyance and (especially) Monarch, as their graphs suggest an exaggerated version of this. I'm hoping that the SA6 gives a bit more body to notes in this range. I'm also hoping that the less energy in the 2-4khz range will give the Dunu a more natural sound than the often artificially bright S8.
While I love the Fearless S8Z, it has a small spike right at 5800hz that ends up being problematic in quite a lot of music. Cymbals can end up sound overly hot and splashy, so I typically trim that down with EQ about 3 db. Big improvement. The SA6 has a dip there, so I doubt that cymbals will be too hot, but maybe they won't have enough energy. We shall see. I'll be building a EQ preset for that area just in case. The SA6 seems to have a lot more treble extension past 10khz than the S8Z, about the same as the S8, so I'm hoping for a good amount of air for an IEM.
In the sense that Moondrop S8 has lower bass than SA6 or has less punchy bass than SA6?