i havent ried ffof... ff products are hard to find around here, and the one store that carries them is also the single hydro store in my area, so there prices are off the charts.
i have used mg moisture control, with a very limited success.... would go from nute burn to starving plants to nute burn, about every 2-3 weeks. it may have been strain related though.
the best results i have gotten in soil would be with mg organic potting mix, with a handfull of bloodmeal mixed in for extra N. however i noticed that some strains need a lil bloom booster at the end of the cycle, next round i will mix in some bonemeal when i flip to flower, and see if that improves the final product, taste and smoke and bag appeal were awesome, it just seemed that they were lacking in potency. the organic potting mix holds a shit ton of water like coca based mediums though, you have to be careful to avoid overwatering