The Heili has 2 (or 4) main rotors and is thus stable and relatively easy to fly apart from spec. Maneuvers such as abrupt release the throttle etc, then he comes quickly reeling. When flying interesting to look at (which I personally do not particularly like the military look). Also suitable for beginners, where you can achieve fairly high airspeeds and perform challenging maneuvers. Flight time, stability, robustness in crash etc. are good for the price range! Missing actually only a switchable lighting ...