There are potential closer and older sources but with these distances the most credible reports will more than likely exhibit a behavior that attendees will find difficult to describe. Please post any that report "skimming", ie appearing to warp and vanish and reappear over short distances, any barely visible or appearing to warp heavily, stretch out and vanish. Conventional locomotion though possible isn't efficient over longer distances.
Those reports relating to performance 2-5 times current craft are more than likely local sources with a far more unexciting explanation. Specifically those around 10 years ahead of current specs. I'll leave you to think about why :)
