This is very simple: Craft and place a block, and your area is protected. Most players can understand and use that easily. Drawbacks are that you may need a lot of these protection blocks - in places given by the mod and not by the demands of your building - and that there may be places on your server where nobody can protect the land due to overlapping protection.
Use this if you run a server with inexperienced players and/or players who don't plan anything too complex.
Expendable, simple to use and reliable. What's more to say about a protection mod I am right? Additionally as this is their mod you can most certainly be assured they will be there for any concerns or bugs that may arise. :)