When I opened Zenbivy’s ultralight sleep system and saw instructions for a video tutorial, I was skeptical. Why do I need instructions to sleep? But after snoozing on the Bed 23 all summer long, I’m a convert. Zenbivy’s hook-and-loop system, explained in the videos, allows for more airflow and a wider range of movement without skimping on warmth. Plus, the integrated pillow stays put all night. $280.