They probably ain't using it right. Before foxfarm came along, I used hyponix from kmart+perlite- it worked good. Haven't tried the FFOF but the cocoloco is good stuff.
I agree Canna coco is about as good as it gets for stuff that looks like dirt that you can grow plants in. Pre-buffered and RHP certified pest free. FFOF is fine too, but you can run into issues with old or improperly stored bags. Fresh bags kept inside should be fine. Promix is the same, fresh stored Indoors is usually ok, but It can come with issues even fresh. I call it Gnatmix.
I agree Canna coco is about as good as it gets for stuff that looks like dirt that you can grow plants in. Pre-buffered and RHP certified pest free. FFOF is fine too, but you can run into issues with old or improperly stored bags. Fresh bags kept inside should be fine. Promix is the same, fresh stored Indoors is usually ok, but It can come with issues even fresh. I call it Gnatmix.