I went to a Mizuno fitter over the weekend. I more or less also wanted to be sure I was using the right shaft. I currently have Dynalite XP Gold R300 in MX200's. On the optimizer, all 3 swings were 87.3, up slightly from last time I was measured, but well within myself. I cant remember the other numbers, but the shaft came back as an S300. This shaft felt heavier. There was very little, if any, change to flight and distance. I did not try any other shafts as this was the recommendation from the computer. Maybe I should have, but he was very happy with the way I was hitting the ball. I have to say, the fitter was very helpful, asked a lot of questions, but he was helped by my feed back as well, so it goes both ways. You have to communicate back what you are feeling when you hit the ball, kinda like a help me help you situation. At least I dont have to go through the expense of changing shafts and I can concentrate on my golf instead of wondering if what I am using is right for me.