I was struggling with new xxxxxx Pro irons. Received a master fitting where the Titleist T200 and Steelfiber i110 S was my best fit, and boy did that combo feel great! When I couldn't get an agreeable exchange, I opted to keep my new xxxxxx Pro irons but replace the shafts with the SteelFiber i100cw S shafts, and waited for the clubs to be shipped back to me. I hit about 10 shots on the range, and headed out to the course for our Men's Quota game. Justified the new shafts on the 3rd hole, a 150 yd par 3. I aced it with the 7 iron, which did happen to be one of the clubs I had hit on the range. That Pro V1x went right back into the bag! So I had an Ace in the first round I played with the new shafts, with maybe 13 swings in total on the new clubs.