Originally Posted by mm9u

Getting to Pusan is always a nightmare from Incheon, and getting worse rather than better. Most of the country lives in Seoul, and there is not enough regular traffic to support the flights from ICN to PUS. Most people connect through GMP, or take the train up. With more and more Asian destinations served direct from PUS, it becomes easier to avoid ICN entirely.

From ICN, there are both morning and an evening flights, everyday on Korean Air, but the morning flight is not everyday on Asiana. If you can time your arrival, it does make connecting a lot easier.

Getting from Incheon to the train station in Seoul is easy, even in the brain dead state of having just flown 16 hours. There is direct bus service that is fast and cheap, and everything is well marked in English. The KTX train ride is nice, with some wonderful scenery along the way. The upgrade to first class is nice, but not really necessary. If you want a real train experience, take the local (Mugunghwa) train down. Much slower, but a really interesting slice of Korea.

Living in Pusan, I do not recommend that you ever fly NW. NW flies NRT-PUS, but the level of service is much lower than on any other airline. Japan Airlines will get you directly into Pusan, with a change in NRT or KIX.

I usually fly JAL for the service, even in coach. It is possible to fly KE LAX-NRT, and then connect to KE NRT-PUS, but you may have a hard time getting KE to realize that.

Long haul to Incheon, you have the choice of Asiana for safety, or Korean Air for service. Myself, I fly Cathay Pacific, and connect in Hong Kong. Indirect and insane, but it allows a stop in a great city, and is a lot more comfortable in any class.

As always, your mileage may vary.

MM9U, living in Pusan for the last ten years or so.