Dunno, I've tried every way of growing possible (except aeroponics and aquaponics) and think NFT is by far the easiest and most convenient (no media to wash, dispose of etc). I don't use rockwool, instead I sprout seeds in a tiny netpot with seramis clay (probaly two tablespoons at most) and then put that in the system when the roots show through. I don't even use the film anymore as it seems to work fine without. I guess the only problem I get is the plants often grow way too big for my needs.