My personal opinion would be...
Do not worry, do not touch until something goes wrong.
Like less power reserve than it use to have, too much force needed to hand wind it, sudden gaining/loosing time.
In the meantime, enjoy.
There are no rules to apply about how long a chinise rep last, could be 3 days, 3 mothns, +3 years.
Usually I would say, if the unit you receive is somehow faulty, the problems will arise really soon.
Also take into acount after +two-three years is likely to happend a new improved version pops up at a cheaper price. However, that's not the case of your 111.
Sure more "expert" menbers could give you their five cents, too.