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.
Each person is different depending on their age but in general, healthy adults need around 7 hours of sleep per night, with children and older people needing more. Teens typically need nine or more hour per evening, with younger children needing ten to fifteen hours for restoration.