Pros: Nice planes & attendants. Clean.
Cons: Had to get off Korean air in Seoul & go thru terribly bogged down customs, just to transfer & continue on another Korean air plane - both ways! Barely made it to my 2nd plane even though I practically ran thru the big airport after the customs delay - both on my way to Hanoi & on my return. Got to Vancouver & only found out by accident that my checked bag would NOT be transferred to my Seattle flight, even though my tag clearly said to pick it up in Seattle. Had to disembark, claim my bag, then go thru the departure procedure at Vancouver all over again, with 2 customs checks: enter Canada, re board to U.S.