Cisco Flexible NetFlow is a method for configuring NetFlow (as opposed to a new version of NetFlow.) Flexible NetFlow extends the use of NetFlow v9 and can also be used to configure IPFIX. You can see this in the Cisco Application Visibility and Control configuration (Cisco AVC).
When trying to configure Flexible NetFlow (FnF), you should generally add NBAR to the export. NBAR has been supported in Flexible NetFlow since October 2009. If, however, the router is running a more recent version of IOS (post version 15.2(4)M2), Application Visibility and Control support is available. This includes support for NBAR, performance monitoring, performance agent, and several other areas of NetFlow.
Cisco Application Visibility and Control
Cisco AVC reporting provides insight into:
Response time between packets within the flow as well as packet loss, retransmits and several other details
URLs, though these can only be exported with IOS version 15.2(4)M2 or more recent
NOTE: The Cisco AVC solution is provided within the Cisco Integrated Services Routers Generation 2 (ISR G2), Cisco ASR 1000 Series Aggregation Service Routers (ASR 1000s), and Cisco Wireless LAN Controllers.