I bought a bunch of these batteries:
http://www.amazon.com/gp/product/B0072A ... UTF8&psc=1
I run twin 2200 batteries, a gopro, FC40 camera and some other goodies and can get over 12 minutes of aggressive flight time. I have gotten 18 minutes of nice smooth flying when concentrating on having good video. I have no problem with adding a gimbal to the mix. Sure, it is heavier but it is still super stable and if you know how to fly your craft, it's not an issue. Apply simple physics and you will be fine. If you send it ripping towards something, be it a tree or the ground, it will 100% take a lot more room to change directions.
Here is my current build weighing in at 2.8 pounds.
Phantom FC40
Twin carbon fiber outboard battery mounts
Carbon fiber anti-jello kit w/ front FPV mount plate used to relocate FC40 camera
Gopro Hero2 naked w/ DJI loop attachment mounted to carbon fiber anti-jello mount
Carbon fiber rear FPV mount plate used to mount Lipo alarm
9.5" P2V props w/o guards
LiPo alarm w/ balance cable extension