I can fall asleep almost anywhere. I routinely fall asleep in the break room at work. Once, I was helping a friend fix his car, and I fell asleep on his garage floor when he went inside to get water.
But in a hot metal tube tearing through the sky, with my neck all kinked? Get out of here, man.
The clouds are pretty. But speaking from experience, connecting flights/long flights will just let you drop in and out due to exhaustion. You will randomly wake up because of the weird positioning of your neck like 5 times. Heaphones help a lot to sleep. But I conclude, quality sleep can be found on airport floors(not joking).