I very nearly went for the ST Mini, but I REALLY don't want to step into rebuilding, or even give myself the option, because I'm sure I'd like it too much! I want to keep my juice consumption low, too, so the smaller tanks appeal. Plus, I'm a mouth-hitter and I hear the Minis are a little uncomfortable for that, with too much airflow even on the low setting. These Nanos will be just a little experiment for me in producing a teeny bit more vapor and putting a little cotton in the mix.
IMHO I say that you can get a mouth hit just fine to suit your preferences at a slightly lower wattage. Either the wide open, 2 hole, or 1 hole AF adjustments will work for most vapers... if not then just dial in the large slot to half, third, or whatever amount of flow you want. It doesn't move around so easy to lose your setting.