Firmware Question: ASUS ac1750 or Merlin ac68u?

I’m a newbie looking for info on current firmware available for a new ASUS RT-AC66U B1 (h/w version A1).

For the last several months I've followed the forum discussion about the suitability for this router of the Merlin ac68u firmware, but have lost the thread about the pros + cons of how it compares to the most recent ASUSwrt versions for this model. The router will be used in a very plain vanilla network but I appreciate the refinements that Merlin has offered.

Thanks for your...

Firmware Question: ASUS ac1750 or Merlin ac68u?