The DSG tune is a minor upgrade. For me, the most obvious issue with the DSG once I had gone stage 2 (added torque) was that at very light throttle cruising the DSG seemed to have trouble deciding which gear to be in and it would go back a forth but only under those specific conditions.
Going to a DSG tune corrected that hunting issue. I didn't use APR DSG tune but what I liked about my stage 3 Uni DSG tune is that it holds whatever gear I am in unlike less aggressive tunes that would downshift if I hit the detent at the bottom of the throttle. I used GIAC tune several years ago and it did correct the issue I mentioned above but it would not hold a gear if I hit the detent.
Anyway, it is an expensive upgrade with subtle returns. By that I mean when you put a stage 1 engine tune on, you feel like wow this is a very noticeable change. You won't get that with this upgrade.
It is a tune you can live without but one you do notice if you lose it.
I have had a different experience, however, I also did not go with the APR DSG tune. I got mine done through 034Motorsport.
Let me preface this with the following:
I would've gotten the DSG tune from APR, except that they didn't want to give me the time of day, even knowing that the car is S2+hpfp, and RFD from them.
Because of that, 034 was offering a discount @Wuste, and since I live in Vegas, and was going, it seemed only fitting that I use them.
That being said, I am extremely happy I did.
I feel like difference from s1, to s2, was not as noticable as stock to s1. Getting the DSG tuned (S2-DSG) was, for me, just as noticeable as going from stock to S1!
It feels more like it should've been this way from the factory. It feels less laggy, and the kickdown switch is gone, so that definitely helps!
I even put my car back in the stock tune, and it still feels like S1! It's like the DSG knows what I want, before I do, and is extremely responsive! Shift points are much better, and uber fast!
I really wish I would've gone with the DSG tune, before going S2, especially since it's my DD.
YMMV.