Here is what my 1521/1Y on 6S does:
http://www.youtube.com/watch?v=EFoYkI_-v_M
Go to 2:36. My truggy weighs around 13lbs maybe more with that set up. I've switched to 5S2P and it weighs even more, but I get longer run times and the power loss isn't that much lol.