[Almaviva]

Do the test run quickly, are they clear and readable, do they help find regression problems, is it reasonably easy to tell what went wrong when they fail, does the time and effort and peace of mind saved exceed that invested (over the life of the project, amortized, sometimes, for the value of iterating quickly)?

These are important questions, whether you call a test integration, functional, or unit, is not an important question.