I personally like AquaSoil (and similar versions) very much and this kind of substrates make my life easier (they have nutrients, the grain size is perfect, it's already done so no mess with other stuff needed and it looks nice... additionally I am not a fan of supplying high amounts of nutrients in the water column, so it is perfect for my lean dosing scheme). In a few words, it is expensive but it is worth for me. I am a bit skeptical about the other products mentioned, especially when you know what they are. I am not an expert on soil chemistry and I am not denying their potential role on the system, but it looks to me that very basic things will have a much more relevant influence on the final result (water changes, co2, nutrients, tank husbandry, etc.), isn't it?