A lot rides on the tow vehicle and what kind of trailer. Longer the wheel base of the tow vehicle, the less susceptible to sway. The lower the center of gravity of the trailer, the less susceptible to sway as well. Tongue weight setup is also a major driver for all sorts of trailer behaviors.

I have a club cab, short bed 1500 and when I tow my 26' travel trailer, even with sway control you can feel it at times. I think it is due to the high center of gravity and how much wind it catches. It is fairly tall due to the side slideouts and leaf spring suspension. Towing in high cross wind situations, like I encountered in South Dakota with up to 50 mph gusts, if I didnt have sway control would have been dangerous.
My enclosed 24' car trailer is torsion bar suspension and sits very low. I rarely feel it do anything behind me. Both have the same Reese Dual cam hitch setup, just with different weight ratings on the load bars.

The incremental cost of sway control in a unit like the Reese Dual Cam is worth the investment. It is a proven design that is simple to setup and use. It may make some noises at times during low speed maneuvers, but thats about it.