Be careful about what you 'read.' There are people that like to create issues where none really exist and then over think things. In day to day operation I notice no difference between my m1 and m2 in terms of heat or battery. They both are cool and they both run forever (i.e. all day long on battery under normal use). I do charge my devices every night, so I couldn't tell you if one got down to 45% one to 50%, to me both run great.
Apple silicon is really good at figuring out what it needs to do to get the job done and sips power accordingly. So only when it NEEDS all 10 cores running max will it generate heat and use extra power, and I like having that headroom when I need it (not often). I have seen the videos under artificial conditions that try to set up that this degrades performance, and they try to say worse than the M1, but the reality is no, the M2 does trump the M1, even when it gets hot. Which, btw, never does under normal day to day.
edit: I should add, that while I don't notice a difference between my M1 and M2 day to day in terms of heat or battery, I do enjoy carrying and working on my M2 more. I like the brighter screen, the better sound, and even the more squared off design makes it easier to carry in my opinion.
