@Emiel1 That's it! You solved the mystery! Complaining guests must all be sleeping in the wrong direction 🙂
A strange thing about my guest room- it's quite an odd shape (I designed it that way) and the single bed in there only fits in the room one way in order to leave room to walk around. It's sort of tucked in with only space for the night stand next to the bed. Almost everyone who's slept in there, guests, family, and friends, have commented that they don't know what it is about that bed (it's not some super expensive mattress), but they haven't slept that well since they were a baby. It's oriented more or less east/west, but I think it's the fact that it's tucked in there, sort of womb-like. I've slept in there many times myself and I find the same- I actually sleep better in there than I do in my own bed.
@Branka-and-Silvia0 And, contrary to those feng shui rules-, the bed directly faces the door- so when you're laying in the bed with the door open, you look on on the trees, the birds and the jungled hillsides. Rules, shmools. Like you said, it either feels good or it doesn't.