Posted on RWI that this has perked my interest. My only real question is whether this SA4140 will be a potential time bomb like SA3135 were when they were first released by noob if I remember reading right and whether or not Yuki will then make a SH4130 that can then take gen parts in the future to improve reliability etc aside from a service. Exciting times ahead though in terms of movements!
Yuki never made anything They simply re-sold the movement.
I have several SH and SA 3135 movements all running perfectly. The problem is not that they are any worse intrinsically than a 28XX . Parts are the problem. So long as we can ultimately buy the movement alone. There will be no real problem. Each movement has all the parts.
Most Chinese movement leave the movement makers in good shape. Then the Rep assemblers get them engraved. The movement factories won't engrave, because so long as they don't, they can work pretty openly. The engraving of back plates is usualy done with no or minimum tear down. Then damage happens. The movements are stored , pending engraving, in poor conditions and are not stripped and cleaned before casing up.
Ninety % of the problems with Rep movements result from this issue.