The IL surely will look differently between the two, and just from first looks, the chained version may be a few nanoseconds faster (I just like saying nanoseconds.), but it's nothing to consider refactoring your code over. If it looks cleaner one way, I'd take that path.
It always bugged me, how StringBuilder.Append
would always return itself. It causes one to think that the StringBuilder is an immutable structure, when it most definitely is not. It is also especially annoying in F#, where you have to explicitly ignore what it returns. But whatcha gonna do?