FWIW, My experience one of the major South Korean shipbuilders "STX" leaves me in no doubt that their product, despite claims to the contrary, was far from impressive.
They opened a yard in Dalian, China and their record was very poor.
I was sent to inspect equipment that was meant to be installed on a new vessel they were constructing.
To cut a long story short. They had several vessels in the yard that were left rotting as the clients refused to accept delivery due to shoddy workmanship.
The particular ship I was overseeing was so bad that the shell was carriaged, due to it not being sailworthy, to a yard in Norway to be stripped down and practically rebuilt.
The only reason it wasn't brought to the UK was political as the owners had Norwegian connections.