I recently came to know that XBee modules from Digi use Silicon Labs chips and the Silicon Labs ZigBee stack, so I ask, if I can use the Silicon Labs chips directly with Simplicity Studio as well as the ZigBee stack to create a ZigBee device, why would I need to get XBee modules at all?
Silicon Labs have modules as well as the Mighty Gecko MGM12P Module for Zigbee and Thread which is multi-protocol and provides much more flexibility having 1024kB of flash and 256kB of RAM. This means that instead of having a processor for the application and a separate ZigBee module I can have both the ZigBee connectivity and the application within the same module.
I'm just trying to understand the justification for an XBee module vs a more versatile Silicon Labs module (on which the XBee modules are based).