After today's run I'd say Maru Kala (H2H) is pretty much identical to the Katana post above. 1000-2000 TP was around 40k, while 3000 TP was pretty consistent 60k with very similar set that I posted a page back.
Overall Maru Kala appears to be worse than Victory Smite, except that the weapon is pretty good at boosting the damage of Victory Smite thanks to the Crit Rate and PDL aftermath.
I don't think its base stats put it ahead of Verethragna, but maybe at higher stages???
On the plus adding a strong distortion option really did open up monk skill chains. An easy 4 step: Maru Kala > Shijin Spiral > Smite > Smite is actually better than previous options we had. Using Maru Kala as a skill chain option or to put up AM felt like the right way to use it, it's not designed to replace anything we had before. Spamming it is probably not the right way to use it.