I find newer developers benefit more from unit testing than older ones who had to learn from the school of hard knocks of the pitfalls that could make something fail. Unit testing does not lead to good design - it just leads to a design that is more testable. You need to test your code but the way unit testing is preached is dangerous. "It will force you to design your code better", "How can you test whether it is correct?".
I prefer to have well written structured code that when you read it automatically tells you simply what it is trying to accomplish and how it does it. Functions/classes should be small and concise. They should only have one responsibility. Unit tests don't protect against logical errors.
Unit tests give more false positives than anything else particularly when a project is first written. Good design trumps tests - tests should be the verification stage nothing more. I never bought into the testing comes before everything else concept. In my experience this line of thinking favours testability at the expense of extensible code (may be ok for throwaway projects or one off utilities but ironically unit testing isn't as important for these).
