When the 09s came out I was curious about the "upgraded rear bumper" as well. Reg tow has a stamp on it somewhere says max limit is 10,500 lbs.
Max tow/upgraded version had stamp said 11,500 lbs.
Hitch and bumper are kind of incorporated so ugraded bumper, also means upgraded hitch.
So if were talking about that part of the pkg, there is an actually mechanical diff, but would it really apply to that many? Thats a different debate.