From a technical viewpoint the Asian 7750 suffers a whole host of problems.
Firstly, most A7750's suffer from poor amplitude even without the Chrono running, standard versions are better in amplitude. Fire the chrono up and you can loose over 40 deg
Positional error is usually large due to incorrectly installed jewels and poorly formed/finished staff pivots
Gear depthing is poor at times
General tolerances are poor, which explains why some get good and some get bad. Poorly tolerance movements display wear marks on bridge surfaces and component's. obviously this wear debris floats around the mech and creates further issues down the line.
Poor quality materials, especially the ones used in spring areas
However, my biggest issue with ANY Asian movement is inconsistent electro plating on certain parts. it is just piss poor!!. It is poor in quality and adhesion to the parent metal
After cleaning and servicing, check your movement out a week or so later and you may find bits of plating floating about in the mech, kinda defeats the objective of a service. The A3135 suffers this problem also, along with poor quality winding gears.
To balance these issues, you have to look at cost. An A7750 is at least half the price of a serviced used gen. And in fairness to our Chinese friends they are slowly getting better. Our Swiss colleagues do have somewhat of a head start over our Chinese friends, lets face it, its difficult to catch up on over a hundred years of movement manufacturing.
I'm sure these issues will be addressed in time and we will then have a stable movement to work with.
