Fact is, people say terrific battery. And I was looking forward to terrific battery. But I get the same as what my Lenovo would give me.
Maybe I was just already spoilt and lucky and expect8nh too much. 6 to 8 is still much better than 5 years ago.
The discussion about the MacBook Air and you are comparing to a MacBook Pro 14". I have both laptops and the battery life of the Air under heavier use is definitely better than a Pro. This is not surprising, the M1 Pro/Max have double the number of performance cores, the efficiency cores run at a higher clock, plus the Pro has active cooling and a brighter display. At the same time, the battery of the 14" is larger, but not twice as large (49.9 vs. 70 Wh).
I think for regular users, getting two day battery life on an Air is pretty normal. For instance my wife regularly used her Air for two work days before charging.
When using it for work, I get approx 6 hours.
I'm confused when people report 20 hours usage. I'm guessing this is during very light work and it looks if sleep time?
FYI. My previous Lenovo p15v also got approx 6 hours. That was a great laptop as well - as good as the new MacBook, just without the looks.