I've been visiting this McDonald's lots of times over the years. On my latest visit (August 31st 2017) I discovered there were large bugs running on the floor in the inner section of the restaurant 🙁
Wasn't too pleased with their service. I'm a foreigner so not too familiar with the KRW notes yet. Meal was 6100 and I pulled out 60000 instead and they said something pretty rude about it.