It really is annoying when it goes off when you're moving slow and trying to avoid a stall, it seems like its going off unfairly in that instance. But I've only had that happen to me about twice, ever.
Overall I wish it was set more aggressively, especially at airspeeds over 200 or so. Its stupid that when you get someone's near six you can't shoot them due to them moving randomly instead of the way an airplane would presumably actually behave.