@whonat I would lean that way, although I know I can clear Incheon Airport in Seoul in under 30 minutes with a family of six and I've strolled through check-in and customs in under five minutes there. Korea is exceptionally efficient and believes in over-staffing as a rule.
It's always a catch-22, isn't it? Leave a lot of time, and then breeze through wondering why you were there so early; or get stuck in really long lines with no extra time.
@LianaBrooks
Hmmm. I think I would have at least a 90 minute window. Customs is your wild card.