Every systems has downsides and upsides.
I read an article from Wageningen University and their these researchers thought that the tiny bubbles in DWC cause too much movement for the roots, which might be the reason for the plants becoming more vulnerable for diseases. It was not a claim, but they thought that that might be a reason the plants got sick and thus got root rot. I don't know, and they also did not know for sure.
A risk with both waterfall and DWC is that when you have a huge, really dense rootball, that the water inside the rootball stagnates. It is not in contact with fresh oxygenated water. Only the roots on the outside of the ball get enough DO. No risk for this with E&F. But with pump failure, roots in E&F will be dry. If you don't notice within 48 hours or so, it at least gives the plant a shock. Not always dead as some think. Pump failure in DWC will at least not make your roots dry out. Lack of oxygen could be a bigger problem.
So when people say: My system is better, they always forget about the not so good sides of their system.
In the end it is all about: Does your plant get enough Water+DO+Nutrients? If the answer is yes, then the system is good from a biological point of view. Maximum DO is easy to reach. A waterfall, bubbles, a pump on the bottom pushing water up and make a bulge, E&F, sprayers.
I have seen all kinds of systems, and a lot of people claim their system is best. But I never saw a hydro-system that had a significant higher yield then 600 grams per 1 square meter within a shorter period then 10 weeks under 600 HPS. Sure with CO2, but that is not hydro
Sometimes people have a higher yield occasionally, but they would have had the same yield with other systems as well. But a system that continuously and with several growers performs better... did not see it.
Another thing: Does it suit you? If I sometimes see the systems that people build with fence posts and tubes, and sprayers, and God knows what, I want to give up this hobby. But other people think 'easy peasy'. That for me is important. What I like, others may dislike. Does not mean my system is better. It is better for my situation and my 'fears'.
I for example drowned plants in soil in past. A lot. The reason I switched to hydro. My friends who are still on soil and coco think I am an idiot. They think hydro is too much work. I also love how clean hydro is. They don't care. I am afraid of leakings. That is why a system with all those connected buckets would be a nightmare for me. I would get up every morning and think 'hope it all stayed put last night'.
So everybody has his angels & demons.
sorry for the long post.