Like anything, it depends on what issues you are having. Compared to the stock setup, in feedback from customers I am hearing better startup, tunability, and driveability (mileage), but this could be because they were already having issues.
I know I am going to regret posting this since there are so many variables I will just be guessing. From a performance point of few, it really depends on what we are comparing to. If you are running the stock CCCI, I would guess around 800hp. Obviously higher with the DIS4 until it fails which 90% do. Compared to a dizzy setup, I would guess they are much closer.