My suggestion is to go see a certified fitter for determining the correct shaft. Although most golfers can get more speed with a lighter shaft, lighter shafts don't always mean that you going to get more distance. I was fit at the Titleist Manchester Lane facility. Like you, I don't have a high swing speed but ultra lightweight shaft don't work for me. I have found that heavier shafts improve my tempo significantly which leads to more consistency and hitting the center of the clubface resulting in better distance and accuracy. You are definitely going with an awesome driver but take the time to make it the perfect driver with a good fitting. Best of luck.