Like most people, I sleep differently in different beds. Most of the time, it's obvious that I like some beds better than others. But there are two types of sleep patterns I experience where I'm honestly unsure which one is superior.
Imagine a typical, decent night's sleep. Not absolutely blacked-out bliss, but pretty solid. And when you wake up, you feel relatively awake -- not Woody Woodpecker-on-meth chipper, but in a good spot to start the day.
The only difference is that in bed X you naturally wake up relatively early (say, 8 AM) and in bed Y you naturally wake up relatively late (say, 11 AM).
So, which is better? On the one hand, you could say that bed X gave you the same level of restfulness, but in a shorter time period. It's more efficient! On the other hand, bed Y gave you the same degree of restfulness for longer. It's sustained quality!
Obviously, one way to check this would be to see how you feel at the end of the day. But that's tough to do, given that one's tiredness at the end of any given day is reliant not just on the quality of sleep you got before, but also what time you woke up and, oh yeah, the activities you engaged in that day. So I'm trying to rely on intuition, and it is failing me.