Bottom line: I would run the tests myself, but I don't know enough about .NET internals to create accurate results that can be used as a reusable guideline.
You don't need to know .NET internals. You just need to know what your performance requirements are and what your typical usage is going to look like. Profile the code under a typical usage scenario in the all the variety of ways, and choose that which meets your performance requirements and is easiest to maintain (i.e., don't necessarily choose the most performant; there are other criteria).
