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.
Much depends on when you need to or are able to wake up each day, and how much sleep you are getting. 1  There is some variation from person to person, but generally adults need 7.5 to 8.5 hours of sleep per day. 2  Children (5 years old and up) and teenagers will need more sleep than this, ranging from 8.5 to 11 hours.