My scratch built fpv wing can fly upside down. Just sayin'...
I'm quite surprised to hear that the fit of the components was so poor. Not sure what to make of the flutter. I haven't pushed my fpv wing that hard, but am pretty confident in the rigidity of the xps foam covered with the thin fiberglass.
I designed mine with time aloft in mind. I wanted to come up with something that could carry multiple cameras and be airborne long enough on a reasonably sized battery (3300 mah, 3 cell) so that the battery weight didn't dominate the payload.
From the review, it seems like the X-8 does a nice job of doing just that. Plus, I really do like the looks of it. My fpv wing V2 is going to have a longer nose, more similar to the X-8 and be tipped with a clear dome to keep the camera totally enclosed while allowing movement. I think that will be a big improvement over the X-8.
I would REALLY like to see a build video on the 360 degree angle camera mount David built!