Both Google and Numpy look better than, and don't seem that different than, standard Sphinx. I'm actually going to change my projects to use that napoleon extension.
Long descriptions are a good thing! =) I do agree that the Numpy style is a little lengthy, but also does seem more appropriate if the descriptions are longer.
Next question is whether to document just the public API, or all functions/methods. Presumably, all private functions could use some sort of quick and dirty documentation, or, it could be mandated that all functions/methods are fully documented (or at least that's the goal).
I'll open an issue on github so this all stays with the repo with an enhancement tag and link to here .