From the dealer I ordered from, it was said to be non-refundable since its locked to your VIN. And with the transparency mode there are a number that say they've gone to the dealership with it and it didn't show up on a scan.
Xtreme you also have the stick. That was with the automatic. The gains with the stick probably are far less. I will report back in 2 weeks on my fuel economy with the Eco mode tune on my car. Since thats about how long a tank lasts. So far according to the DIC its already reading higher on the average with the same driving style. I will say when driving though and looking at the instant mpg reading, it almost seems to read lower though. So I'll just have to wait and see when I fill up.