You're incorrect, the finish will not be inferior to what is on the Apple Watch, because you're not understanding the core differences. Apple never specified PVD over DLC finish, furthermore, they are separate entities with chemical versus vapor. . And What I stated was entirely accurate with both examples prior. But you're not factoring the differences of the materials of how they are applied And for what applications. Physical Vapor Deposition describes a variety of
vacuum deposition methods which can be used to produce
thin films and
coatings. The Most common applications are automotive parts and firearms against corrosion and oxidization. The concern with physical vapor deposition is that overtime, it can peel or started to degrade.
The only purpose of diamond like carbon coating is to assist with sustainability and prolong the life of the product. For example, DLC is very common in the medical field for internal replacement parts for longevity.
The case of the space black Apple Watch, DLC is a much harder coating over a PVD coating. It's Possible they could use the same process, but both coatings are completely different and are not comparable on how they are applied. Diamond like carbon coating is a much more efficient and sustainable manner to protect the product versus PVD.
https://en.m.wikipedia.org/wiki/Physical_vapor_deposition
https://en.m.wikipedia.org/wiki/Diamond-like_carbon
http://www.pvd-dlc-coatings.com/
https://www.chronext.com/journal/mechanics/a-timely-question-–-the-difference-between-a-pvd-dlc-coating