Two entire days spent making a branch where git-annex uses ByteString instead of String, especially for filepaths. I commented out all the commands except for find, but it still took thousands of lines of patches to get it to compile.

The result: git-annex find is between 28% and 66% faster when using ByteString. The files just fly by!

It's going to be a long, long road to finish this, but it's good to have a start, and know it will be worth it. optimize by converting String to ByteString is the tracking page for this going forward.