Just to provide a point of reference for how much overhead we're talking about here: we use the recommended setup from factory_girl with `FactoryGirl.lint` on Whetstone. With this setup, a single spec which uses no database access reliably takes around 80ms. Adding the `FactoryGirl.lint` call brings it up to around 400ms. We have around 50 factories. This means that adding `FactoryGirl.lint` adds 320ms in this example.