3 weeks...mmm about that. well i would say as long as you dont add nutes for quite a while and the plants have good roots established its awesome. after the better part of 2 months vegging my runoffs still read 2k+ppm, 2.1 ec. until that changes i wont add anything but some tiger bloom once i get them flowering. definition of "hot" is high in nitrogen and means that very young, weak, poor root systems will get the blowtorch effect. any soil can work. foxfarm and similar companies design the nutes and soils to be used in stages. start off in light warrior, get good roots going, transplant to ocean forest or happy frog get them nice and transitioned then start adding the feed etc. i started using it only because i cant get topsoil and make my own mix in the winter.
as long as you are aware of the pros and cons and can adapt to them you can work with most anything.