I tried the Apex ribbon with a single Adire AV3 and as an MTM with 3" tangbands.
Sparkly highs, a lot of resolution but not easy to listen to for hours. I did nothing fancy, just a 3 mF cap and an L pad brilliance control. The woofs were uncrossed.
25k? I have no idea.
I prefer the small Audax TM010 for $10