Hey I have an idea - bbPress could just use the backend and run standalone so it's far faster and lighter than WordPress ever was.

Oh wait, we already had that - it's called bbPress 0.9 and it was fantastic.

The tests that are published on that site are kinda useless - no WordPress install operates in a single-page-at-a-time-to-a-single-user - you'd have to test it under load from multiple connections - the impact of one plugin may be a fraction of second but with a dozen connections to the server, some things scale very poorly.

You also need to test first page load and then second page load to see if the plugin behaves differently and for logged in and non-logged in users.