We recently built a 12 footer at blueEnergy in Nicaragua, and put a very light tail on it.  Nice to see it furling at about 500 watts around 7 or 8 m/s windspeed.  Furling does indeed work very well but it does really need 2 things:

sufficient offset and
correct tail moment-or-weight.  

If in doubt offset it plenty and start off with a light tail.

I usually find that wooden blades work best on the AWP but they do have some pretty sturdy GRP blades now.  Not too sure of the shape...  The tip pitch is usually much too coarse for me but they work.