So I've been transitioning our entire media collection to a Plex server. Two really big comments:
1. Plex is the only system I've found with robust parental controls that work in every possible way. User profiles with PINs. Broad rating level controls. The ability to change controls for individual movies/shows without having to change their given rating. A library that only shows the content available for the user. Broad cross platform compatibility. It's my new gold standard for parental controls.
2. Good lord, formatting media to work on a Plex server is time consuming. Some of it goes very quickly, but the stuff that's left after the easy part...yikes. And if you have stuff that's not in one of the TV or Movie databases (for example, workout videos), good luck making it work on the first try.