One issue that comes into play, is minimum gradabilaty, IE 12% per current specs. If going up grades steeper than this, you may not have low enough gearing togo up or start on that grade.
Another. Spec is 35 or 40 mph minimum speed on a 5% grade. Is that fast enough for your butt!
The rating you are looking at has some minimum standards....whether they meet your minimum standard is another story issue. Mine is 45mph and 30% grade. Reality is, manufactures tow ratings suck, and are to low! My 02 mind you!
Marty