If you want to do basic things quickly, such as list out a PDF's fields or fill them up, this is a great module. The module comes with scripts that do this for you.
However, if you want to do anything deeper than consume the meager utility functions you are going to have a problem. A great example is trying to check checkboxes. This is impossible. The fallback would be to create something using a font that looks like a checked checkbox, but who knows how to do that with this API?