I'm aware that recursion vs. iteration is one of more controversial of hints listed. There is certainly class of problems are much easier to solve using recursion than iteration. That is a hint for problems that can be solved equally easily with both methods (like fibonacci).
There is also a problem that various people find either of methods "simpler to understand". There's some point in providing both implementations, so both groups can find easy-to-understand algorithm.
Probably some weaker wording should be used. --Taw