[tomgallard]

Although TDD does give you more confidence to make changes to your code in future, I think you're overlooking a major benefit, which is allowing swifter code/test/debug cycles.

So rather than having to make a change, run up the app in my browser, and manually test that the latest bit of code is working, I can test individual functions just by running my unit tests.

Of course this doesn't obviate the need for browser based testing too - but it can reduce the amount of it you need.

TDD allows me to produce working code faster by helping me notice and fix my errors sooner. If you're an excellent coder, maybe you don't need this- but I certainly do!