>Test-first units leads to an overly complex web of intermediary objects and indirection in order to avoid doing anything that's "slow". Like hitting the database. Or file IO. Or going through the browser to test the whole system. It's given birth to some truly horrendous monstrosities of architecture.

Oh yes - I agree completely with this.

I'm not sure I agree with testing things with Capybara though. How are you sure your backend controller actions are doing what they're supposed to be doing? Sure your browser might render what you need but what if a model attribute is set to false instead of true? How do you account for that using a frontend test suite?