I've been flying on the new 3DR frame for a couple of weeks now with an hour or so of flight time and have collected my feedback on the frame.
The strap that comes with the frame designed to hold the battery is poor. Mine just ripped off during flight causing the quad to fly out of control and crash. The strap ripped, it didnt come undone, the velcro is nice and strong. I was out flying and was performing some quite harsh manoeuvres to test the handling limits and the battery ripped free - totally unacceptable, frankly.
Only having one strap to hold a 300g 3s LiPo is not enough, there is lots of movement even when the strap is done up very tight. I normally use an additional elastic band or two to keep dangerous play to a minimum.
My previous frame had an enclosure for the battery so there was no play at all when mounted. This provided for much more stable flight and also allowed far easier mounting of cameras under the quad.
While the design of the actual flat boards to mount the electronics on is excellent (lots of places for cable ties to attach boards and other bits and pieces) the spacers and screws used to hold it all together are too weak and the threads degrade too quickly. I would highly recommend using metal (or at least a much harder plastic) spacers and screws at the cost of maybe 10-15g.
The L shape of the legs means there is a huge amount of stress at the corner during any rough landing with any horizontal movement. I've snapped all the legs already over three crashes. They perform very well when taking vertical load and as the demo video in the car park shows, can easily withstand a drop of a couple of metres onto concrete.
My suggestion would be to totally, or mostly, eliminate the L shape and move the mounting holes further out.
Apart from on top of the electronics stack, there's nowhere to easily mount a camera without quite a lot of engineering work to make a frame that can span the battery.
General flight performance
Without a camera and with the battery firmly mounted, my quad flies very well and is good fun. It's a huge improvement on my last frame. I also end up having to dig out bits of field from the ends of the motor mounts after a rough landing as they effectively scoop up mug and grass :) That's my fault for flying like a nutter, though.
The actual motor mounts and main airframe are rock solid and vibration, even without rubber mounts for the main board, is low enough to fly with no problems.
Overall, I like the frame but feel the points outlined above need addressing in future versions with the legs and battery mount being the most important.
I appreciate that none of these problems would exist if I flew my quad in a windless hangar with a foam floor, but that's clearly unrealistic and these frames should be a bit tougher.
I'd like to hear other's feedback on the frame as I've only had it a couple of weeks and am a relative novice in the field.