I haven't used it myself, but have seen it in large scale commercial hydroponic operations. Although it gives some advantages with moisture content management, personally, I wouldn't consider it for amateur use. Firstly, it carries a cost to buy in the first place, then there is all the problems of providing the soluble nutrients to go with it. Then it gets sterilised at the end of the season before reuse. Then there is a disposal problem, and a good chance that the fibres will cause a skin rash. It's even more faff than growbags. Soil is free, delivers the nutrients for free, and gives the crop more flavour. Good enough for me.
