Finally, I've decided to find out just how terrible MG soil really is, and am testing it myself. I'm using MG Potting mix, the kind that "Feeds Up To 3 Months", against Fox Farms soil, which if a 50/50 mix of Ocean Forest and Happy Frog. The only thing added to either of them, is perlite,(approx 25%) so that their drainage qualities are near the same.
I plan to get the verdict, at week 4 of 5 or veg. That should show clearly, which soil is more fertile, or how similar they actually are. I also plan on giving them nothing but Calmag Plus and Dynagro Protekt(silica supplement), via root-feeding, which'll keep things pretty even. All other feeding will be foliar, til it's time for 12/12. Should be interesting.
Here's some pics. They are newly rooted clones of Ice, going strainght into their 4 gallon pots. That should keep things even, plus, prove/disprove the myths against MG burning plants with it's time-released nutes, and also focus on overwatering issues, which it's known for. The FF is in the closest two pots, and the MG is the two in the back.