7D AF in AI SERVO (photos included)

Actually, I use spot AF with AI Servo for photographing tiny hummingbirds.  It's not very good but it's better than anything else.  Also, in my experience and according to what I've read, the 7D has the most difficulty with objects coming straight toward the camera.  That makes intuitive sense to me, because the distance is changing fastest when the object is coming straight towards you (or going straight away from you).

FF