I really wanted to tune my '15 but I spoke with Malone many moons back and they don't have a 100% tune for the DSG. If I remember right, I was told, "We've have about 15% of the old DSG tunes work in the '15." For me, the shift points are the most annoying. Sure, I would like the extra power but, for me, it would be misplaced without a proper DSG tune. In addition, the DSG turn cannot be saved the in Flashzilla so, if a dealership were to reflash it, I would be out both time and money to do it again.
If only I lived closer to a tuner.
The "I'm not going to tune because of my warrantee" argument is not mine. I feel confident in the Magnuson-Moss Act they would have a hard time proving any mild thing I would do to the car would cause any issues. Remember, these are raced in Europe and have a great deal of untapped potential.
Drive safe.