Small mistake in this article.  The original Avata could in fact do rolls and loops, you just had to put it into full manual mode.  The drone was fully capable of doing 180 drift maneuvers, but you ran the risk of it going into a dive that you may or may not have been able to pull out from.  That was mostly dependant on the speed into which you started the maneuver.

The two main suspected improvements  are the better camera, and what appears to be rear facing obstacle avoidance sensors.