The mac os x version of notability with icloud sync was the missing piece to really make notability a must have tool. I use it coupled with my iPad to read, review and comment research articles. icloud sync enables me to transfer back and force the notes between my mac and the ipad without thinking about it.
The latest new feature (pdf support) is really something that was also missing (could not copy a selected text sample otherwise). It’s progressing quickly in the good direction from version to version. I would love to have the same sync possibility with other cloud storage. My instituation has a private one based on owncloud for instance, but no sync, just backup or manual file transfers. One other thing that is missing from my point of view are tags hat are more versatile than directory to organise documents (you can associate more than one tag to one document and thus make it appear through different tag filtered directories).
bruno_grenoble about Notability, v2.0.0