>>502
Not fully related, but I feel like sharing TMI regardless.

I've slept on the floor for years as a kid (true complicated cool story). I noticed no difference in the nature of my dreams during those years.
As a side effect of sleeping like that, I can now easily sleep in any place, but I am never fully comfortable sleeping anywhere (often experiencing periodic limb movement, morning cramps from involuntary stretching, and the occasional episode of sleep paralysis)

Every so often I fall sleep at my desk on a reclining chair.
I definitely have a lighter sleep when that happens, and more than the dreams, I remember strongly the half-asleep phases, and what I hear during them.

If music is still playing when I fall asleep in this way, its sound will take a very distant, comfortable, inviting, and eerie timbre. I really can't describe it correctly, but I know that if someone could accurately bottle that illusion into a VST plug-in, he'd be a very rich man.
And when I fall asleep like that in silence, auditory hypnagogic hallucinations take over. They seem to last for minutes, and are much more vivid than those I'd hear in my bed. Sometimes I've heard amazingly detailed music during these hallucinations, but attempting to transcribe it later is useless.

A few hours after falling asleep in this fashion, I tend to wake up very progressively to illogical "zombie brain" thoughts, eyes open. That phase can last for very long but any distraction will jerk me out of it immediately.

Of course, these effects might be more due to the fact I only sleep at my desk when the right mix of caffeine, sleep deprivation, and free schedule makes me too lazy to even want to take the stairs to my room, than to the sleeping environment itself.