Have been playing around with active tracking this winter (NZ). Most of this video is shot with Active Track on the Air 2s. Found it pretty good although there were not many obstacles to avoid on the ice. I did miss the ability to rotate around the subject (like the Mav 2) while tracking and it took a bit of experimenting to get it to track from the front (near the end). Other shots were on the phone and X2 at the end.