I don't have all KZ's, and those that I have I haven't tested all of them yet (Still unopened my ATE Youth, ED9 Youth and HDS2). I'll just compare to Zircon...
1. Plextone X41M: The king of sub-bass. No where in my collection I have such earphones that actually vibrate, with a tickling sensation inside your ears, like these Plextones, maybe except GEDIAO G400 (which sounds not so good except the bass). The mids and highs are very nice, but not as clear or precise as on Zircon. Again, the sub-bass is insane, much more kicking than Zircon's.
2. Sender F05 are among the most bright earphones I've heard. Yeah, they have plenty of bass, but their mids are vivid and the highs are very sharp, so sharp that the sibilance gets you tired.
3. MOAOL M850 have a massive bass, but the sound signature is almost as KZ ED10's. The bass is punchy and pretty enjoyable. The mids however are slightly off-tone, even dark a bit. Not so precise, not bad as well. Same thing about the highs.
I'd say only the Plextone are a must-have, just for their special abilities in the low-end.
As for you genres - Plextone aren't accurate enough, **** are too bright and sibilant, M850 are slightly too dark for opera and probably classical.
I think Zircon excels in those musical genres.
By the way, I received my Vibro Veritas, so it's measuring time!