My 99 Superduty does not drive nearly as nice as my F150 did. My F150 handled much better.
IMHO you now have a real truck. Your expedition was designed to be a drivers vehicle. It had 4 wheel independent suspension and designed to handle and steer great.
Your new truck is much more primitive by comparison... It was designed to haul a load and it uses more primitive suspension (leaf springs and a solid rear axle) to do it.
These beasts have to be more deliberately driven, then through in the fact that these trucks suffer from "death wobble" and require a steering stabilizer, even in 2wd form.
IMHO the AT tires are not optimal for towing, a good street tread is better.
Like you the first time I towed with my F350 I was underwhelmed. To be honest I still am. My 5.4 F150 pulled and handled my trailer just fine.
Thanks and good luck
