Yup, I agree that we don't necessary need to take the Selenium2 approach. I've been using my fork of Selenium2 for a few months on a large behat suite and I've found it very useful for an exception to be thrown, (Otherwise your test/scenario will fail on subsequent steps instead of the actual functionality).

I see you point regarding API + Mink. Therefore, if we've no need to be concerned how failure is implemented in varying drivers, `CSSDriverTest` should not include `testElementNotClickabledWhenHidden` and `testElementClickedWhenShownByHoverPseudoClass`. Seem sensible?