Materials — do replicas really use the same alloys and ceramics?

From my experience, it really depends on where you get it and how much you pay. The higher-end ones, like the VS factory rolex gmt master II, actually use materials that are surprisingly close to the real deal. The weight, finish, and polish feel authentic, and the ceramic insert looks just like the genuine one under sunlight. I wouldn’t say it’s exactly the same alloy, but it’s close enough that most people would never notice the difference.