RE: HD Motor Brush Wires - Important!
Just a follow up here to re-emphesize what Bruce posted. I think the HD motors are excellent BUT you really have to move those braided wires to the position shown by Bruce and recheck them before every flight. I believe every major crash I've had except one (the 0.8 sec power drop issue) has been from having one of those braided wires in a restrictive position. The typical response is that one of the motors will become intermittent and will cause a rapid angle dive.
One more note is to check the solder side of the wires. I've had a couple of my older HD motors which needed to be resoldered. What happens is that over time some of the strands of wires will break which causes more heat in the remaining strands followed by additional breaks from the heat stress. Resoldering with a little extra solder to recapture the broken strands helps to keep maximum current to the motors and the heat down at the solderpoint.
Mike