IPS matches on pre-canned or custom signature and typically push to match the client/server direction and OS types ( windows unix etc...). It can also mitigate at all layers of the OSI from layer3 and upwards.
APP_CONTROL matches on behavior based on the application usage & mitigates or control from the application layer. It uses application logic and awareness for control
The IPS wil make a bigger impact on thru-put in a full blown deployment
The Fortinet Security Fabric brings together the concepts of convergence and consolidation to provide comprehensive cybersecurity protection for all users, devices, and applications and across all network edges.