Rexlion, I have this hitch for no particular deep reason, it just always worked for me and it's simple and easy to deal with. I also wonder about built in sway under conditions where it's better to have no sway control.
I may not have all of the science down to perfection, some of the of technical terminology could very well be incorrect and my understanding of sway verses whatever condition it should be called, the end result is the same. This trailer and the ones before it and most people I travel with experience the same effects from time to time. I really find it hard to believe we could all be wrong all the time.
A recent excellent article in the Airstream magazine publication goes into a lot of detail on how weight distribution hitches work, how and when they damage trailer tongues, how weight distribution is transfered and where during turns, and what is a sway feature and what it is designed to accomplish. It lays to rest a lot of the hype that is nothing more than advertising by hitch manufacturers that you need sway features or you will end up in the ditch. For decades people towed trailers with much less capable tow vehicles without any kind of sway features and did it just fine. It is good to separate advertising hype from reality and be better informed. It is also important to realize how the sway feature works, what is does not do, and why some vehicles really do not need much if any weight distribution and if they do what spring bar strength is really needed.