Meh....I've mixed them together and added perlite, coco coire, worm castings. I never had any problem with it. Yeah it's kinda nute heavy (aka "hot"), but with the extra stuff to make it more open and airy, it's fine. I water to the point of excessive runoff every time....which depletes all the nutrients in about 3-4 weeks....basically through the veg period. I don't feed them anything extra at all during this time. After all the excessive runoff from watering that way, the mix becomes an inert medium that must be fed, thereafter, with some kind of nutrients -more or less a drain-to-waste hydro system. I choose the Jack's 3-2-1 nutrients and that's what I run all the way to more or less week 8 of flower. After that, it's just plain water until the chop.I've done several runs with FFOF and FFHF as the starting base. You just have to "fluff" it up a bit and then water the shit out of it (literally!)
On the next run, I'm curious to try the Bruce Bugbee mix -which is a combination of regular peat moss, vermiculite and dolomite lime.