All depends on what you are towing and what your tow vehicle is. If you have a rear dually 3/4 or 1 ton truck, you probably do not need WDH or sway, if the trailer is light enough. Anything else, I'd hitch up everything.
(Related to "Murphy's Law" Murphy)
2015 White Hawk 20MRB
2011 F150 Non EcoBoost (5.0)