Hi, I recently purchased some cheap carbon fiber props from china. Comparing them to the stock props, they looked identical in shape pitch, ect.. Upon mounting them on the Dji Phantom, it was flying crazy and almost uncontrolable. I immediately took them off and re-mounted the stock props, and am chalking this up as a loss for being cheap. Any recommendations and are the 9x5 Graupners good or GWS 9050 worth purchasing?