Using it right now. Nutes are a little off balance. Used for side by side comparisons and alone, it did minor nute burn on established clones. Also it does drain EXTREMELY fast with nothing added. I think the makers are now just mass producing and not caring about how much of what they are putting in.
In the mix with perlite it helped with nute burn, drained even quicker, but my roots exploded in this mix.
In the mix with perlite, vermiculite FFOF it held TOO much water. Too 7 days for the plant to start using all the moisture, almost dampened off the plant. I dont reccommend using too much water retention with the new FFOF, it doesnt need it.
ALSO keep in mind, the nute burn was from JUST the soil. I have not added nutes to my plants yet for the purposes of side by side comparisons of the soil mixes. The nute %'s are DEFINATELY off.
Overall, it was the best choice to go with despite all the concerns. It has the best stuff to start off in and it does feed your plants for 1-2 weeks for sure. I recommend it even with the diminishing returns lately, just use smartly and watch your plant and how it reacts so you dont end up with a headache in the end.
Hope this helps