I bought one of these today and test flew a few packs. It's supposed to be a Phantom Challenger but it has a few steps to take before that will happen ! I'll just get right into it and tell you why it's not as good as a Phantom by a LONG way... The default, or "Preferred" mode is SMART, which basically means Heading Lock. That is already crap as we know, it's fun for 2 minutes but then simply tedious. I used it on my Phantom and Wookong bird Once. SMART mode also activates GPS Position lock and Altitude control. Altitude control is a bit weird though, the throttle stick is ratcheted, like the original Phantom TX's, and basically put, every click on the throttle is a specific height, kinda.. If you're holding height and you push one click forward, the 350QX rises, say 3ft, another click, another 3ft. if you push the throttle a lot it will rise or descend continuously until you bring the stick into a more central position, but then it makes it's own mind up where/when it settles on a height. So like, if you're descending and want to level out, you are up/down on the throttle trying to stop the bouncing which could be 20ft or higher in magnitude. Stability Mode is GPS position hold without altitude hold. This sounds more typical and more like the GPS mode we love on the Phantom, but the QX is just awful at maintaining a reasonable grip on altitude when you execute the slightest maneuver in any axis. It puts me in mind of a heli which bleeds height at the slightest cyclic or yaw input, but worse because if you try to counter height loss with throttle the curve is so aggressive that the thing ends up climbing out, so now you're up/down on the gas again ! :? :roll: So I saved the worst til last........ I got the QX Hovering in SMART at about 15ft, and then changed to stability mode - WOW. She went down like a sack of crap, hit the deck and flipped. You have to (Wait for it) drop the throttle to zero and pull the throttle trim back to shut the motors down - Yea, really, so the thing is on it's props running at idle while I got the trim button under my finger and shut it down. Unreal, who the Hell thought of that shut down procedure? Here's the problem - the lower and upper part of the throttle curve is for descent and climb, the middle area is for fine adjustment of height. So, what I did was climb up to like 30ft, leveled off, then clicked back like 3 or 4 clicks to bring it to 15ft. So now the throttle is in the lower 25/30% area of the curve - right. When I switched to Stability, it just dropped like a stone, that's not nearly enough throttle to hold it at that height, like, how the Hell are you supposed to know that? It was so quick my finger was still making it's way back to the throttle from the switch when the thing hit dirt, I had no chance. I was expecting a seamless transition, like the DJI GPS-ATT switch.. I killed a prop so after I replaced it I tried a few experiments with that mode switching, and I have to say it's just terrible. The worst descriptor you can use with these things is "random", but that's how this function manifests itself. I dare say you could get used to this, and I will, but this is NOT a quad you can give to somebody who never flew in manual before because it would end poorly. Do these things have a firmware update function?