Will depend on your tongue weight. When I towed my 16 ft fiberglass trailer with a 350 lb tongue weight, there was absolutely no squat and a WD would have just put extra stress on my trailer frame with negligible benefit. Your tongue weight will also let you know whether you want to re-distribute any weight off of your rear axle. You may get a little less bounce with WD hitch engaged as well.
2015 Eagle 284BHBE
2010 Ford F150 XLT 5.4 Maxtow, Coverking Seat Covers, Putco LED interiors, Kenwood DNX571TR GPS, Kicker Powerstage, Weathertech Floor Mats and Window Vents, Line-X, Firestone Airbags, Michelin LTX-MS2, LivewireTS 5 Star tuned, Propride 3P