The benefit of test driven development is, you *know* your code will work before you ship it. Although, that is contingent upon whether you've written thorough and proper enough tests.

Regardless, tests offer a bit more sane and to the point code that can be easily passed around to colleagues to be reviewed for errors, etc. This works twofold, you get better tests, and code reviews on the code you are testing.

++ to you for good practices!