Why do people keep saying this? A lower kv will let you run a bigger prop. Get the right wind and it will be great...The prop on a 12s system would be sooner small and really useless for 3D. I personally thing this plane needs 8s. The power in the Aerobees videos looks a bit anemic for my taste. I am sure 6s 5000 are completely adequate. But 8s would be AWESOME!