People spend 1/10 of their life on the road, yet you buy a car worth hundreds of thousands.

People spend 1/3 of their life in bed, so I installed yesterday
8 SleepPod 5 Ultra.
Then I compared last night’s data from Whoop and 8 Sleep:
The HRV and resting heart rate monitoring errors between the two are very small, within 2~5%.
The sleep onset time error is not large, with Whoop being only 4 minutes earlier than 8 Sleep.
The wake-up time error is slightly larger, with Whoop being 26 minutes earlier than 8 Sleep.
During 8 hours of sleep, comparing sleep stages between Whoop and 8 Sleep:
Errors in wake time during sleep and sleep efficiency statistics are very small.
REM sleep stage percentages are 25% and 23%, with small errors.
But in deep sleep, percentages are 33% and 17%, with a huge error.
In light sleep, percentages are 37% and 60%, also with a large error.
The temperature AutoPilot of 8 Sleep seems to have a subjective improvement feeling,
feeling cool and refreshing when cold, and warm when hot,
which needs further experience.
Another point is that the Ultra version’s reading mode can lift the mattress,
which is immediately noticeable for those lying in bed reading or watching TV,
providing comfort and spinal/neck protection.
Other improvements will require another one or two weeks of sleep data to analyze trends.
App interface parts (Figures 1~3) and data comparison (Figure 4):