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 person's sleep cycle is about 90 minutes, so you either want to take a 25-30 minute nap, or you want to take a 90-minute nap, depending upon how much time you have and how you want to feel when you wake up, says Breus.