That's not quite the range of the Phantom 3 Professional, which managed 2,500 feet without issue, but it's better than the 1,000 feet I got with the Phantom 3 Standard in open space and the 400 feet it managed in suburbia.
Medical specialists with a public voice like Dr. Oz should absolutely be encouraging people who are sleepy to sleep more. However, arbitrarily applying eight hours to everyone is actually harming people who simply need less sleep, or those who actually need more than eight hours.
You can follow or contact Melanie Pinola, the author of this post, on Twitter. Getting enough sleep is critical for good health, but the old advice about needing eight hours of sleep can vary by person. A better way to find your optimal bedtime is to conduct an experiment to find when you naturally wake up.