Where are you dumping the rockwool? Granted its smaller and less mass than the soil/coco but you miss out on reusing which is for some a huge plus to put it outside and utilize the soil and make it earth again...
I've done hugos and sure they are light weight and cheap but never was satisfied with the texture and way hydro burns even at low ppms. Looks and smells and yields are solid though! Presoaking cases of hugos sucks though, imo. Work is work, I went back to soil but I was born a soil boy ;)