Right now my favorite soil is Kellogg Patio Plus and I'll explain why... First, It's only $5 for a 1.5 cu ft bag. Second it has mushroom compost + kelp + worm castings + bat guano and beneficial organisms. Third, it's made locally. Fourth, it's organic.
I also have plants sitting in Roots Organic ($18 per 1.5 cu ft) and Fox Farm Ocean Forest ($16 per 1.5 cu ft). Yeah they're good potting soils, but not three times the price good. Growth is equal across the board. And this is my third year testing all three side by side. A little personal rule I've learned in Biology class. Never trust results unless you can duplicate them at least three times. I've done it and this will be my last year that I ever use FF or RO. Complete waste of money.
I also looked into Sunshine Mix and BioBuzz. I didn't test them like the three mentioned above, but I did feel them and I wasn't impressed. I've been looking at Higromite Silica Stone ($20 for 21 liters) and Hydrocorn ($40 for 50 liters), but they're really just fillers and don't compare to potting mixes. When I do look at fillers, it's hard to be the perlite ($4 for 0.4 cu ft) and vermiculate ($5 fpr 0.4 cu ft). Perlite is neutral while vermiculite acts like a buffer and adds Calcium, Magnesium, and Potassium.
I swear I'm becoming bitter because I'm starting to hate everything I see in the hydro shops. Anything pitched to cannabis growers is always ridiculously priced and over hyped. But what can you expect when you had former drug dealers go quasi-legit. lol.