Flew to 400ft for the first time, descent rate seemed so slow and I was afraid to come down straight too fast in a confined area with trees all around.

Did DJI reduce the maximum descent rate to eliminate VRS, or is it still possible but much less likely with a P3 ?

At first at 400ft  I thought something was wrong and it was not descending at all, then I increased the rate and could finally perceive it descending.

I am guessing that as you say, DJI reduced the descent rate to try and avoid VRS.

Aloha IMI and Geebax,

     DJI did not make the connection between VRS and the reduced descent rate, but they did note that it was further reduced (and it was a good thing).  Also, though I have not noticed it in my own P3 so much, the angle of the rotors have been changed from the P2 Ver. 2 (Vision +).  If a change of angle is present, it works to break-up the VRS in a quadcopter.  

     I regularly go up to 400 feet and come down very quickly - or so it seems.  The boredom of descent is broken up by covering horizontal distance.  VRS can occur at an angle if you are traveling directly with the wind.  So determine the wind direction and head into it with a rapid descent (well, as good as it gets).  Otherwise, come down in a large spiral or otherwise cover large real estate in your descent.  If you do it right, it can get quite invigorating.

     It is very rewarding for me to see you two discussing VRS so casually and matter-of-factly.  In the P2 days, it was denied that VRS could happen in a quadcopter, much less a drone quadcopter.  I had to go into the back room of Wikipedia to get them to admit that the physics of scale required that VRS be mentioned in the same breath as quadcopters on their VRS page (Descent Under Power) and the quadcopter page.  The fellow who did the VRS video on those two pages did us a big favor by demonstrating what it is and how to get out of it.

Aloha and Drone On!