In the past some Korean sets were indeed somewhat lower quality. But right now, English (and European languages) are of way lower quality than Korean imho. I don’t collect Korean cards in particular, but I do collect all 14 languages, and I like that Korean is one of them. Coincidentally, I received a Korean Team Aqua’s Secret Base from the Double Crisis set to complete that full Korean set (the others I pulled myself from a Korean Double Crisis booster pack a couple years ago).
Here is the Korean ‘Pikachu around the World’ part of my Pikachu collection, including history about Korean cards in general, in case you or anyone else is curious (picture-heavy, so don’t open it when you have limited internet - e.g. mobile network).
Greetz,
Quuador