I never buy ANY of thier overpriced, foreign made crap.
You're right, what would the Japanese know about making swords.
Plain edge for sure. I have one serrated one, a dedicated "boat knife" for cutting lines/ropes if the need shoulder arise on the water. I don't use it as a regular knife, trying to sharpen them is a giant pain in the ass.
I've got four Spydercos, three made in Japan, one in Colorado.