Just a friction sway bar works by making it harder for wind or passing trucks or anything else to cause the trailer to sway. Towing a full height TT feels a lot different from a pop up and the wind has a lot more square footage to push against. I recommend a sway bar for any full height TT.
These sway bars are passive. You hook it up when you hitch up.
A better option than friction sway control is built in sway control in some weight distribution hitches. These prevent sway rather than try to control sway. If you don't need the WDH then just a friction sway bar may be all you need.
2015 Coachmen Freedom Express 292BHDS Blue Ox WDH
2015 RAM 1500 4X2 CrewCab, 5'7'' bed, 3.93 gears, 5.7L 8-speed VVT, Payload 1608, Max tow 10,400