I have a 2003 Silverado K1500 with tow package. I have a pop up and tow it using a 2 inch ball and standard 2x2 draw bar with the proper amount of drop to tow the trailer level. I also tow using tow/haul mode.
WD hitches are overkill on a pop up and should not be used as they can damage the lighter A frames on the front of most pop ups. I have a 2000 Fleetwood Sedona and the owners papers specifically warns against using a WDH.
I never had any problem with sway even when I pulled it with a 1991 Isuzu Trooper with 2.8 liter V6 that I used to own, but my trailer only has a 10 ft box and no slide out.