Originally Posted by
greg99
If we wanted to clear customs and go back through security, how much time would you allow?
I did this once when I had a seven hour layover and chose to do the free five hour tour of Seoul (recommend it).
It was quite efficient and no worse than any airport that I've encountered in the past. IIRC it took about 20-30 minutes to clear security and immigration and not even that long to get outside security.