This is really nice! (Like most Core Design extensions). Easy to install and configure with straightforward interface. That is, nothing complicated which is a compliment for this kind of extensions.
If you want to protect specific articles with a password, this is a very good solution.
P.S. It needs the Core Design Scriptegrator pluginn orde to work.
I could only rate the extension as excellent. Still, I would like to make a suggestion. Have you ever thought of adding the option to be able to preview the attached file like in the "Enbed" plugin?
Other than that, as I've already said, the extension is excellent.
In a few words, I can't imagine how anyone could give this extension less than five stars. I have tried it many times on different servers, some of them quite 'stubborn' and 'difficult, and it has always com up to my expectations. A 'jewel' that every administrator should have in his arsenal.
My congratulation to the development team.