All the different types of hydro/aero can be looked at or compared as different levels of aeration or different mixes of water time vrs air time.
One thing you need to know is that oxygen is relatively slow to dissolve in water. The very very very thin surface layer of a bucket of water will quickly reach 100%DO, but the lower portions of the water will not increase in O2 for some time. The O2 is slow to migrate through water from the surface contact area.
At one end is DWC and all its variations. The majority of the roots stay submerged 100% of the time. They depend entirely on the dissolved oxygen in the water. This is why DWC needs constant aeration in the form of air stones, flumes, water falls, etc. You need that to insure that all the water deep in the bucket has the same O2 levels.
The next level up is Ebb/flow. Well, depending on how long you flood. When you flood the roots - with or without medium - you are submerging the roots in deep water. During the flood, the roots can only get O2 from the water - just like DWC. So you also need to aerate the water in the rez.
However, during the drain cycle, the roots will be left with a very thin layer of water coating them - the meniscus layer. That very thin layer of water will absorb O2 from the air relatively fast and can transfer it to the roots much faster than any thick layer of water. That means the roots get an O2 boost during the drain cycle. Longer drain cycles than flood cycles are to be preferred as long as the roots do not actually dry out.
Thats where a medium can be useful. Things like hydroton, rock wool etc hold more water than the roots by themselves. Plus they hold it in such a way that the roots can only get to a very thin layer of it at any given time. That means the roots can stay wet with that very thin meniscus layer for a longer time. This ends up giving them better O2 absorption.
The downside to that medium is its a heck of a lot of trouble. I see no issues with going mediumless as long as you carefully time the drain cycle so the roots do not dry out. Its a somewhat trickier/riskier balancing act with no medium, but a lot less trouble.
The next step up would be things like LPA followed by NFT (if done correctly). LPA floods the roots during the ON cycle, but leaves them in open air slightly better than with flood/drain - but not by much. Most folks are afraid to let the roots dry out and use way too long an ON cycle. You just need to get the roots covered in a layer of water, then let them dry out. Leaving the sprayers on for minutes at a time is defeating the whole purpose and just lowers the O2 transfer efficiency.
The key to best results with all these types of hydro is balancing the wet/dry cycles. There is no “best” number. You just have to let the roots sit with that super thin layer as long as possible - without drying out completely!
NFT has a lot of potential as far as O2 transfer because its supposed to provide that THIN FILM of water. Unfortunately, almost every one over does it here too, and really floods the roots. True NFT provides a “film” of water not a flood of water. If you are flooding the roots, you may as well to dwc.
The next step up would be more exotic types like Membrane Meniscus. This is really the ultimate in NFT. It keeps the roots with the thinnest possible meniscus layer 100% of the time with zero flooding. It can produce some really great results, but is very difficult to do in practice.
After that we get to HPA and AA aero techniques. Both of which keep the roots growing in air 100% of the time with just micron sized droplets floating around. In theory, the roots are never flooded. Done correctly, this is the ultimate as far as aeration levels. The problem is both are more technically demanding as far as hardware, plumbing etc than other hydro types. They also require a lot of finicky timing and fiddling and trial and error. if you over do it with the mist, you end up with roots no better than LPA. If you under do it even a little, you dry out the roots, and that is bad
Many people claim that various different techniques work better than others. I personally find that HPA and AA do produce higher yields - as long as you dont screw it up! However, Im not really convinced the increase is all that much. Maybe 10%-20% over other types of hydro at the most. I think most folks who go for HPA/AA are really into it because they like to tinker with gadgets and gizmos more than for the extra yields etc. I do it for that reason and because Im addicted to fuzzy roots! Any extra yields - if they occur - are just a nice extra.