Documentation under all Products are free to view. User Guides will start with a description of the systems.
Scale and Size of your network is the biggest differentiator, to answer your question, and FM is a good fit.
FlexMaster server NMS can manage ZDs, Standalone APs, 7731 PtP bridges and has Reporting capabilities.
SmartCell Insight sources from FM, ZDs, SCGs, SZ-100, vSZ controllers, and is designed for Reporting.
https://support.ruckuswireless.com/documents/552-flexmaster-release-9-8-user-guide
FlexMaster Overview
Ruckus Wireless FlexMaster software is an intelligent, scalable network management system designed to facilitate administration of your
dispersed Ruckus Wireless Access Points and ZoneDirector devices.
https://support.ruckuswireless.com/documents/834-smartcell-insight-version-1-4-user-guide
Introducing SmartCell Insight
Overview
SmartCell Insight (SCI) is a massively scalable reporting and analytics engine,
designed to collect data from Ruckus network equipment, analyze that data, and
then present it using a wide variety of standard and custom reports.
Capabilities
SmartCell Insight can collect data from the entire line of Ruckus Access Points (APs)
along with the ZoneDirectors (ZDs), FlexMasters (FMs), or SmartZone (SZ) controllers.