Got one of these to review for my website, really happy with it but last time I used it I crashed, not that badly no damage to rotors but now when I take off it starts to rapidly circle in a wider and wider loop till it crashes. It's not spinning, it's quite stable just not fly able was great until that happened.
Sometimes I find the controls not quite as responsive as I'd hoped, and getting level flight is quite hard to do, always seem to keep having to adjust up and down whereas I've flown copters before that we're easy to get to a desired altitude and keep them there.