I built this quadcopter at home with a $30 KK2.0 flight control board and an aluminium frame.
The quadcopter is 60 cm from motor to motor and is roughly 1.5 Kg in weight. After adjusting the P and I gains it is very stable in the air, however my cheap remote control gear produces hysteresis making it impossible to zero the trims. When I get a bit of time I will attach a GPS module and see if I can automate the flight.