The Members Only Sections in GoCentral are extremely basic. For the most part it is just to share information with a select few, for example announcements for employees only.
I realize that GoCentral is an extremely basic web site builder, that's why I am using it. If possible, an add in for a membership plugin would be a nice next step. For now, looks like I will have to rebuild my site in WordPress.
User authentication would need to be tailored around your membership access needs so a solution like WordPress would be better suited as it can be expanded with a countless selection of 3rd party plugins or even adding custom coding. GoCentral is more for what I call 'business card' style websites.