I use a Reese Trunnion Bar EQ system on my Buick Roadmaster wagon pulling my 18' open car hauler. No issues except one time while doing a near 90deg turn backing, one of the bars fell out of the deadhead. Never had an issue with sway on an open trailer - unless it was improperly loaded.
However if I ever replace my trunnion setup it will be for one of these Anderson setups
http://youtu.be/HRoQ_yQZQwQ and it has a "built in by design" sway control. Everyone I've talked to that have these setups are ones pulling campers and they say it is the best hitch setup they've had and so easy and quick to setup. The big problem is that they are about double the price of a round bar or trunnion setup.
BTW, the trick to not getting a drawbar/deadhead stolen is removing the thing when not in use!!! It's a pet peeve of mine to see drawbars sticking out when not in use ready to shin me.
My
worth, DanC