In some cases maybe, but it's not effective in my case. In order to catch failures in this particular component, the most effective thing is to check that a large set of invariants is still true. An integration test of some kind only checks for behavior; does this component work when interacting with the rest of the system? That can show a failure exists, but is not useful for showing why. It's the unit tests which continually check the large set of invariants that can really get to the why: if a particular invariant is no longer true, the path to the problem is usually clear.

Maybe that should be a number 6): easily tested invariants.