scale????
I have a H9 Edge w/ oS 160 it used to weigh at 13lbs 2 oz Now after carbon gear wheels and so on.. 12lbs 9oz
I would bet youe scale is off or test on concrete.
also at 10.5 lbs that os should be pulling that plane like crezy. and the 18/8 mezlik
is what i use and I love it...
Scott