Darn useful! Even though Test::Pod::Coverage usually bites me just when I think I'm ready to release a module, I still love it. It saves me from sending a lot of undocumented code into the wild -- and this is the code that makes it go.
It's great, but it's easy to misunderstand the interface and use it incorrectly so that it looks like a module passes Pod::Coverage tests when it doesn't.
Also, there are no hooks to handle inheritence. If a Foo isa('Bar'), then when Foo has methods which override those of Bar, Pod::Coverage doesn't recognize this. Sometimes that's expected behavior: maybe you should odcument exactly what's changed. But sometimes you document it differently, and do not want to list every updated method. It would be nice if there was an option to recognize when this occurs and ignore them.
Pod::Coverage is a very useful module that, when used in another module's test suite, should help improve that modules documentation by a great deal. Of course, developers are free to insert empty documentation stubs for their methods, but those willing to do that don't need Pod::Coverage to remind them of the lacking documentation in the first place.