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.
The average adult should get about seven to eight hours of sleep per night, according to MayoClinic.com. Pregnant women may need a bit more; shoot for about nine hours. Try to stick to a sleep schedule, going to bed at approximately the same time every night and getting up at the same time every morning.