Hello All, I finished out my F550 and I put a Pixhawk autopilot in it. I also own a DJI Phantom 2 with Zenmuse gimbal. I thought I would try something different than the Naza for this build and I have been very happy with it so far. My Phantom 2 with Zenmuse gimbal was purchased from the photography side of things and it is great for that purpose. The gimbal with the gopro is a lethal combination. http://youtu.be/oax7iPSHtAQ video from St Thomas, USVI. I purchased the F550 to FLY FLY FLY and FLY it does. It is fast and crazy and maneuverable. I fly it even when it is way too windy. It is rock solid fun. It will also fly exactly like a Naza when you have it in that mode. It is a very configurable system and flies very well. There are several aspects that are the same as the Naza ( Loiter on the Pixhawk = GPS hold on Phantom, there is simple and super simple which corresponds to Course Lock and Home Lock on the Naza) There is also fully autonomous flight with unlimited waypoints. Follow me mode where it will follow your phone. Circle mode where it will rotate around a point with camera always pointing towards the point. In autonomous mode you can also set it up to circle every waypoint once with the camera pointing at the waypoint before it moves to the next. The software is open source and for 100 bucks you get great telemetry for it that will connect to your laptop, (PC, MAC, or Linux) and the same telemetry will hook to your phone or tablet. (again iPhone or android). One other trick that I really like about Pixhawk is the reset to armed yaw. I have set one switch on my transmitter to 'reset-to-armed-yaw', which basically just yaws the helicopter back to the rotational position that was front when it was armed. This is very handy for reorienting yourself without having to go into simple or loiter mode. This is not a fanboy post. I love my phantom, I got it for Christmas and it was love at first site (with multirotor aircraft) I bought a 550 frame and was going to put a Naza in it and just started looking around, and the pixhawk caught my eye. The downside has been that it is constantly evolving hardware and you have to make sure that any instruction or youtube video that you watch deals with the hardware that you are using and not two generations ago hardware/firmware. The tech for this has been through many generations to get to here and some of the "information" on the web should be pulled or marked as historical. this is the video that got me thinking about the Pixhawk. http://youtu.be/SdRZuQiS7G4 Mark Miner - At work but wish I were flying my F550!