Coming from a guitar background, the idea of not just immediately putting new strings on any instrument I acquire has never really occurred to me. The strings that were strung up at the factory serve only to do rough initial setup, and verify that the instrument plays/sounds good. After sitting under tension for months/years, they won't sound any good. With that being said, I suppose it would be a different story with basses, because the longevity of a set of strings is much better. Still, it would be a rare occurrence that an instrument comes from the factory with my preferred strings installed. Plus, it's easier to just put fresh strings on when I set the action and such to my liking.

). Feel free to have your head explode over my usage of "mismatched" "sets"