It varies on the lipo I use. If I use the stock Lipo once I hit 5 mintues I better have landed by 5:30 minutes. If I'm using my Dronefly.com lipo which is a 2250mAh 45C lipo I can go to 6 minutres and be on the ground by 6:30 minutes. I can push it on either for an additional 30 seconds but once it hits the first fail safe the second fail safe comes in rather quickly and it starts decending. It would not be so bad but with the gimble and HERO3 onboard, due to the additinoal weight it decends too rapidly for my taste and you pretty much bounce off the ground. Not good!!
Aside from that, this gimble is awesome, phantom and HERO3 combination is awesome!!!