Here is my 2 cents worth. I just did 6 days in SW VA on the AT. I have one of Brian's new SpinnUL tarps, 11'x10'. Monday night last week the winds must have gotten to around 40 to 50 mph during the night and heavy thunderstorms.
I tie off with 550 cord for my ridgeline to the straps and use the JRB tensioner lines for guy lines, tied to MSR groundhogs stakes. Nothing moved all night. Only problem was I had to abandon the hammock and move into the shelter for safety from falling limbs and trees. Hammock and tarp were just like I left them the night before.