First of all I'm very happy with DWC (so far the best way in my opinion), second I notice a little anger on your tone, third "cheaped" down system? how much should I spend on it? a million dollars to be good... regardless, if you are going Hydroponics you better have D.O... and right now I'm not talking "supercharged" or "superoxygenated" I'm just talking about noise, water splashing, bubbling, pumps and etc...
No anger. I really don't care if you waste time, effort or money as it is not mine that is being wasted. It is sad though thatyou are happy with a system that is very near the bottom of the pile as far as efficiencies and about the top of the list when it comes down to problems. It will however grow pot and to many that is about all that matters. As far as your opinion on the the need for high DO. No aeroponic system or inert media hydroponic supplied with nutrients from chemical fertilizers that is properly designed needs high DO water in the reservoir or delivered to its plants in water from the reservoir. Over 99% of the plants roots oxygen needs are supplied by oxygen from the air surrounding the roots. Such systems are sucessfully run using nutrients that have almost no DO and do very, very well.
Natural levels of DO are quite adequate as the amount of O2 in air is 21% or 210,000 ppm, while the DO in water at say 68 degrees (in low salinity water) is only 8.81 ppm The only real need in non artifically high DO growing systems is to keep the reservoir water in an aerobic state.
DWC, NTF , small tube aero and bubble ponic as well as systems with water running through tubes channels and what ever that need the water to have artifically raised DO levels need this because they are cheaped down and or barely usable systems that fail without the artificially high DO levels.
It is really not a matter to debate, just a matter of fact.