F150 3.5 Ecoboost-length and weight of camper you're towing

We are now pulling a Laredo 331BH with a 2014 EB max tow crewcab short bed. 38' long from hitch to bumper. Combined truck and trailer running around 15,300 lbs (Cat Scale). The truck pulls good, not great. We have taken it from Ohio to Wisconsin and back. Plenty of HP, a slight issue with sway/wiggle. Much better with the correct bars on the hitch, have narrowed some problems down to the P tires. Looking to upgrade to better tires in the spring since this year is winding down. We only have a few short trips planned.
We are using a Blue Ox sway Pro with 1500 lbs bars.