Economy mode 87 octane= maybe slight mpg increase but the tranny shifts are much firmer.
Performance mode 91+ octane= lots of power even more aggressive shifts. I loved this mode and used it for about 9 months, then switched back to economy (simply to save a few bucks on fuel) and really miss the added power.
I never used the towing mode, but I can tell you even going from economy to stock is a huge difference.
I have gone back to stock for a couple visits to the dealer, and dreaded the ride home (My Avy in stock mode is a real dog and the tranny is a real slop box without a tune)
The only problem I have is that Edge does not have the option to turn off AFM (cylinder deactivation) which I would love to be able to do.
Otherwise I love the unit but as mentioned earlier mine does not have a dimmer feature, and I found it too bright at night, so I just program my Avy and lock it in the glove box.