So to summerize:

ATF = origional spec, but is now outdated
Ford Honey = GL-4 gear lube
MTL = GL-4 gear lube

both are very similar viscosity

Friction modifier is bad, and hasn't been recommended by Ford.

Current official recommended fluid from Ford: Ford Honey.

Still up for debate: whether MTL is an acceptable alternative

Are the lab tests comparing MTL to Ford Honey at all? Should they be?