*This ^^^ I wish this was better understood. Whenever I see a claim of improved distance I am always skeptical because so many variables are uncontrolled. But the biggest variable by far is the terrain and flight profile with respect to trees and ground clutter. When I see a claim of 15000 ft distance, I usually find someone flying from high terrain over a valley, or a slightly elevated beach over open water, with very clear radio line of sight between RC and AC. But those very same high performance antennas and amps wouldn't even make it two blocks through the dense tall trees in my neighborhood. I generally have to fly straight up out of a cul-de-sac, about two hundred feet in altitude to safely clear the old growth forest that with its 145 ft canopy. I feel lucky to get 600 ft distance to make it to the next cul-de-sac. With the rollings hills on top of that, it is just not a good environment for microwave datalinks, particularly at 5.8 GHz.
But I do understand that the only way to make a valid test is to try to eliminate cultural clutter and trees from the test environment. I'm not criticizing those that report their test results this way. Otherwise we'd never be able to compare one system to another. But new users should understand, that those distances are best cases, and real world distances in normal flying could be far less, mostly depending on the propagation path. Keep in mind, the total propagation path loss between antennas can be anywhere from 40 db to 250 db, depending on the path distance, and clutter. So a few extra db of antenna gain on each end can make a big difference in distance on a clear path, but would be not even close to overcoming the big path loss numbers you'll find in a very cluttered path.
