I know I myself and others have mentioned on multiple occasions that we desperately want/need alerts for Netflow and QOS. It still baffles me that neither module shipped with this capability day one.
I can think of many use cases for this, I list a few of the better ones:
-Alert when traffic class X takes up more than X percentage of the pipe
-Alert when any single session takes more than X percent of pipe
-Alert when the priority queue goes past X percentage full
-Alert when a traffic class begins to drop or discard traffic
For me this would be a HUGE deal to know when these types of event occur as they would generally point out a problem.