I'm trying to figure out what the changes are between the Mavic and P4 with regards to the downward sensors.  I know that they are used for hill climb and for more accurate indoor / low gps positioning, but is there really an object avoidance feature (like we see with the front sensors)?

From what I've seen in person and in videos from hand catching, there isn't any avoidance, but people still talk about it chasing away.

Maybe Ken or someone else from DJI can talk about what the hardware and software will do with the bottom sensors and when that kicks in.

Ken, any thoughts?

Hi, I just got my Mavic on Friday and flew it for the first time today.  No significant issues, but I did experiment a bit with the downward sensors, and yes, it notifies about the vertical clearance and as well does chase away from hands underneath.  But I am surprised, I thought the downward sensors would be used mainly in terrain follow and in Vision Mode (is that opti?).  I'd still like to understand what the advances are here vs the P4 (software vs hardware as well).  Ken?