A good friend of mine "Doc" Austin recently gave me an APC 12x6 to try on my EF Extra EXP. The prop I was using was a Turnigy Wood Light Electric 12x6 prop, and I wasn't getting the performance I was expecting; it was good, but not great. After about 3 seconds in the air with the APC prop I felt a HUGE difference! Not only was there more power, but the airflow around the plane and its control surfaces was smoother, and I could FEEL it. I was utterly amazed!
Anyway, here's the video. Enjoy!