Subsystem Protect Block Parametric vs. Protect Refernce Model

Hey,

I've folow question,

What's the mainly different betwwen the Subsystemsave by setting the Block Parameters to NoReadOrWrite and get in an Lib-Block or convert the Subsystem in an Referenced Model and get a protected Version from that.

I need it for third party application.

Best Regurads Andy

PS: If I wont youse the Verion via Referenced Model, need I some other toolboxes?