They began to make the move around 18 months ago....at first they were sharing production between Korea and China and now they're solely MiC.
From what I've seen first hand the Korean models were finished better than the Chinese models...but for the most part they're the same construction...materials etc.
I've just recently bought an SG43 MiC and it has a fair few flaws...BUT it WAS half price.
I couldn't really justify $800 for a flawed guitar but $399 sat well enough.