IMHO, there is a difference between what Photoclam did with the Multiflex and the Sunwayfoto GH Pro head vis a vis the AS D4.
AFAIK, the Multiflex is an almost exact replica of the AS Cube. You'd be hard pressed to find any substantial difference other than the accent of customer service. I bought and enjoy the Cube.
I wanted to buy the D4, as I wanted a lighter geared hiking solution with a slimmer profile. If you compare the D4 and the Cube, the weight difference is really minor. Not a solution for me, since I already have the Cube.
If you look at the specs of the Sunwayfoto GH Pro geared head, it is much lighter than the Cube. At 670g it's lighter than the D4. It is smaller too. This is not a 1:1 knock-off. If (that's a big if) the GH Pro is a solid and smooth performer, I don't see another option in its weight class for a geared head. It is enough of a weight difference to the Cube for me to consider it.
Our "US Sunwayfoto distributor" was oblivious----and was
not helpful to me in their replies.
There may be a high quality American answer on the horizon but its not here yet.
ken