I hate to belabor the point even more but the consensus is for NA XFires that the Eurocharged tune doesn't do much for throttle response? I was under the impression that the tune would eliminate the need for a Sprint Booster until I read this thread. I would eventually like to get both if they are both needed/beneficial but I'm more concerned with throttle response initially as proper downshifting is a PITA with the sluggish throttle in my XFire and it's the one thing I don't enjoy immensely about the car.