Our Frontier is now 10 years old with 105k miles.
The weight of our camper varies between 4500 and 5000 pounds loaded to go with a tongue weight of about 600. We have toted it out west and all over the east coast with nary a problem. When totally loaded for a long trip, we are very close to being maxed out on payload. However, we are still under the max for either axle by a couple hundred pounds each.
We tow at 65 mph, about 2500 rpm in 4th. It will maintain 50 to 55 going up a 7% grade, dropping into 3rd or 2nd and running at 4000 to 5000 rpm.
We do get a nudge from a large truck bow wave when it passes us, but that seems to be par for the course.
I have owned all manner of trucks and by far this is my favorite.