Especially the regular/smaller one looks really really tiny at first sight when first unpacked- with an old bulky laptop besides it. Buut i got used to it and love the smaller size, which, cause of the small frame/bezels around the display, displays everything just right! After a while it doesn’t seem that small and fragile anymore. All this talk about the tranfer speed is, if at all, important when you transferring huge files and media. For a regular user you don’t notice any difference. Get the model right for your wallet and needs. Rather spend some money on more ram. But oc more local storage is handy. The 15in by default comes with a 10 core gpu, perhaps slightly better perfomance in graphics and it has 6 vs 4 speakers. But the speakers on the 13in are really good (in my opinion). Also the trackpad is larger. Battery wise, they will last about the same time. So, smaller or larger sceen! Everything else is the same… keyboard, resolution, ports etc. Battery lasts a full day with ease. Depending on usage… eg watching yt or content 10-15h/ browsing, watching, working ~ 10, maybe more hours. Light usage brings you to the next and often even to the following day.

FWIW I get all day battery at the office on my 15’’ Air. Beyond that I don’t particularly care. Even if my machine has only smart charged to 80%, I can usually make it to the end of the night.