Personally I'd go with DL for the extra legroom. I'm 6'2" so the added pitch and recline is a big benefit.

Oh and how come 3 segments with DL? Are you doing something like LAX-SFO-NRT-BKK instead of LAX-NRT-BKK?

Regarding the SWU comment, that would require an M fare ticket which you probably know are quite expensive.