Minor nit: Tie::IxHash provides a facility to maintain insertion order. Any relationship of this order to a sorted list must be done by the user.^* On the other hand, Tie::Hash::Sorted does provide a very flexible and relatively efficient way to keep your hash sorted regardless of hash modifications.

I am not advocating using tied hashes without proper consideration but rather trying to clarify a common misconception about Tie::IxHash that others seem to have.