I meant to add that you can see a Hacker A20-22L on a 16.85 oz AirfoilZ Yak 54 with a wingspan of 40".
I flew mine and made a video for their website... please look at the power and not my flying... I kinda suck...
http://www.airfoilz.com
then click on the videos button...
It rockets out of a hover and that's a Gen1 1320, Hacker A20-22L and Hacker ESC with an APC 10x4.7 slowflyer... It levels out at 17 amp at full throttle and drops to like 9.8 volts... 166.6 watts.