I prefer the old style weight distribution hitches and I see the add on sway control as a positive. There is no reason why one can't tow great. I had the fortunate opportunity to tow with the same hitch both the dual friction bar set up and the Dual-Cam sway control. There was absolutely no difference in how the trailer handled and the sway prevention on both. That's apples to apples comparison..same basic hitch.
The real key to sway prevention has nothing to do with the sway control...it has to do with the set up. The trailer must be loaded correctly and matched to the tow vehicle properly...the weight distribution hitch must be set up correctly.
Integrated sway control force you to use the sway control at all times...yes even in the times you may not want the trailer to track straight...such as on an icy road or gravel roads where you are towing.
Add on sway control also gives you the option to have just a weight carrying shank (forged preferably) with sway bar mounts welded on. This is a great back up solution to keep you towing if your weight distribution hitch head fails and it lets you keep sway control. Been there done that and I will not tow a camper with out a back up solution to get the camper home if a hitch head failure occurred.
Thanks!
Jeremiah