SOT is not only deppendant on how much screen is on... it mostly deppends in your data signal, and the app that is running.... Its not the same 3hs reading a pdf, 3hs playing some game, or 3hs during all day...
you maybe can do 4hs SOT in 4hs usage, but probably after all day you cannot pass 3....
Axon is not really good in battery, do the job, but not for intensive users...
In my case I do 3 hs, after a year, battery seems ok... but I need a charge in the middle of the day mosts days... with 15-20 mins of charge is enough...