The concentration of nicotine in the juice is a little misleading. If you vape 12 mg all day long are you better off than someone who does 36 mg a few times a day? There are so many options available to vapers that smokers don't have, it's hard to compare.
If I were allowed to post in the grown up section I would ask "What amount of nicotine per day (mg x ml used) do you need to stay off analogs" and then ask for details.
It seems that with options, various people have gravitated towards a more unique experience. Some go high so they can vape less, while others go low and vape more. I guess it all depends on if they want the 'nic hit' or the calming after effect (or both). And don't forget some people have juice stingy anemic attys while others have juice guzzeling oral fog machines.