This is a good module.
I have used it in my module CM::Permutation to generate permutations.
My only problem with it is that I think the identity permutation should be
generated before any other one,so the current generation order should be reversed, or the interface should provide some method for doing this(but this is a personal preference).
The documentation is clear.
The interface is ok except for what I mentioned earlier.
It's easy to use and overall I will give it 5 stars.