Tried another free extension first, but that didn't support PhocaDownload.
I'm using this really great extension in combination with the plugin for the extension PhocaDownload.
It's working very well and works intuitive and is build on access for handmade groups in a horizontal layer, on which you can set access-control.

Separate controlling is possible for articles, menus and modules.
You get much flexibility and userfriendly, efficient management in the Joomla back-end.

You're getting a splendid extension for a respectively little amount of money.
Seen the excellent and very quick support that you get from this company it's the money more than worth!
They even did a nightshift to help me!

Thank you Helix, you did a great job!