The issue seems to be what you do in the 3khz range. M3s and M40s seem to be "almost" as revealing but also seem to show less sibilance as a result of a dip in the 3khz range.

I suspect that the "less sibilance but equally revealing" speakers would also have a bit of that dip but not sure. Comments ?

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8