Finally I have read the whole thread. Whats wrong with the Aps version of the DD movement? Had a BBR back in the days which had stuttering hands. But i guess that was a myiota mod, not a dandong?
This and other recent releases are big improvement over previous iterations as it is a true clone movement. On APSF the movement shape is correct, the double barrels are functional, the escapement is in the right place, the keyless works details are functional, the clear shock jewel is real. Lots of good stuff.
Faults:
The metal ribs on the movement seem to be adhesive backed foil, so there is a risk they may eventually come off and some are slightly misaligned. They seem to be better in appearance than ZF but also aren't as "crisp" as the gen brushed ribs. Haven't seen it IRL, looks pretty good in pics.
It's missing the silver threaded inserts visible in some of the "holes" on the front of the bridges. The inside of the holes is just black. Same fault is in ZF and many others but you can see the silver on gen photos if you look closely. Personally this is the biggest current fault, and it's not that big.
It's not free sprung. Visible from rear of movement.
The lower right rib on the rear of the movement near the mounting screw is too short. Only visible from rear of movement.
General movement finish (surface texture of the black, quality of chamfers etc) is rough vs gen (frankly even the $15k customs seem to have this issue)
Movement is probably not made of titanium? Who knows. Not visible, but maybe why the ribs are stickers (if movement is brass, real brushed ribs would be the wrong color)
I think that's most if not all of it. APSF seems to be current #1 in the RM55 world unless you go to the short run $5k++ stuff. The case seems a real winner from reviews and it should look gen from a dozen to a few feet away and still really good at a few inches and genlike unless you're crazy like us.