I'm guessing the big gains with the 4.7 are due to adding a lot of ignition advance at low/mid rpm. I'm about to buy the superchips for my 2010 and use the 87 octane tune. Im hoping it's not too much ign advance when I'm towing my enclosed trailer. I may have to use 91 octane.
Depending on how heavy your trailer is you can tow on the performance tunes as long as you run higher octane while doing so (i.e. 87 tune with 89 or 91 octane, etc...)