I actually went with the Moon 430HA as I read good things and a mint one was available to purchase. I’ll have it tomorrow but my Auralic Taurus Mk2 sounds awesome. I will keep the Auralic Taurus Mk2 as a spare amp.
The moon 430HA is a great amp. Too bad, it doesn't get a lot of love around here. A very neutral, slightly laid-back classy sounding amp that doesn't hit you on the face. And that volume control is simply amazing on the moon. Congrats !
The Formula S and optional Powerman is a great amp for the LCD4, Susvara and Abyss. Oodles of power and transparency. IMO it is end game for any of the top headphones. For the Audeze range I would recommend steer away from warm sounding amps, the Formula S is much more neutral and super fast.