The first time I see AD1,Did not know this AD1.Just study this frame,I identity this frame have a nice folding Small volume,The wheelbase shorter Limited its applicability,The selection of battery is limited, center of gravity into consideration, can only use one type of battery, flight control, battery, receiving and sending FPV equipment installation, high precision, we set up RTF very difficult, and using the fastening screws, folding, head can't hang Mini SLR camera
This is only my personal idea about the technical aspects of the problem, not commercial,
The xc 600 frame based good, strong compatibility, suitable for aviation, folded with 23 x 38 x 22cm,The frame, stable, good compatibility, all parts into the stomach, is the advantage of the frame