ed rosenthal recommends 24/0
you'll see every pro recommend every different method in different posts, it depends on how far back they date,
i personally prefer 24/0 as it saves on time and money and gets tighter node spacing.
16/8 i think its too little light, your going to get a longer veg period,
until a plant shows it's preflowers it is in veg whether or not it is on 12/12 lighting, a plant has to mature to a certain level before it can start showing sex, so if you switch at week 2 then your still going to wait 2 maybe 3 weeks for it to show, and in that time it will stretch a lot as it tries to reach its natural height and maturity, or you can speed up the process keep node spacing tigher, veg a little longer and have it show sex a lot quicker