[pipermerriam]

I think the answer to that question is extremely contextual and going to be very different for different applications. I also think that

I'd like to point out that the idea of including the library code within the contract is untennable at a certain level as contracts currently have an upper limit on size which is determined by the block gas limit. It also doesn't make it any safer because it's still functionally the same as executing external code because it's the same code being executed.