Do not recommend
I hate to say it, but I do not recommend the QR-1, especially at its current price. I got my son one for Christmas, and after about four packs, it's now inoperable.
A couple of things bothered me before it went completely kaput. First off, one of the arms kept popping out on after nearly every flight. Also, I tried all the recalibration tricks, but this thing is finicky for flying.
Lastly, the nail in the coffin, is that the wires on one of the motors simply pulled out, leaving me with a hunk of plastic. Unless I can sell off the thing as parts, it was a waste. My son was heartbroken.