I use the 3.02 fw and I discovered that while descending normally my max speed is 2m/s vertically (and due to a bug in the fw no horizontal movement) but when I did RTH by putting the drone into fail safe it descended initially 4 m/s. For me it was a nice speed bump when coming down from 150m. Then on a pretty quiet day on another descent my drone was no longed descending 4m/s, but 5...6..7 and I could initially hear (and I ignored it first, not really understanding the problem) and then visibly see on the screen that my drone was in a VRS (Vortex Ring State). My first one so I was grateful that I got the lesson high enough. By that moment I had already took over the control of the drone and gave it some forward momentum (no extra thrust) and after few seconds (not right away, it took few nervous seconds where I even managed to think if this was it, the day I loose it) the drone got out of the bad air and all was good. Have not used the RTH descent since. In hIndsight I was lucky that the problem occurred high enough for me to be able to ignore the sound hint that the engines were cycling increasingly erratically and I was able to save it after it had already gotten into a quite the wobble and was dropping quite fast. tl;dr - fw 3.02 failsafe descent is 2x faster than normal one at higher altitudes (it slows down when it starts to reach the destination). Never use it on a non-windy day as then it's a VRS magnet.