nice gadget with potential for improvement

Before playing you have to say where the Sphero 2.0 "rear". That is when a ball is not always entirely clear: o)
The "calibration" is quick and good solution. If the Sphero taxiing However hobbles or slips and thereby rotated horizontally, then he draws the wrong way. This unfortunately happens very often. Even with Nubby cover because the extremely large knobs allow the Sphero on smooth surfaces "huckeln".
This means that you have to calibrate the ball incredibly often in order to control them specifically. Really annoying.
What the Sphero missing is an automatic recognition of the direction from which it is controlled (ie where is "behind"). Alternatively, it could be the alignment might also have a "compass sensor" Remember.

If I can use it once before, I would have issued any 130 EUR for it.
This thing has potential and brings joy long as the orienting direction.