Hi Homer, Good news - if you really liked the NSPro 105T, we will still be offering it in the new 712 irons. If light steel is the way you want to go, we will also be offering the NSPro 850, 950, and the 970's. The NS pro 105T weighs 110gr in a reg and 113gr in the stiff. The XP weighs 113gr in a reg and 117gr in a stiff. The difference is not so much weight as it is only 3-4 grams, but the ball flight will be more of a mid launch instead of mid-high. We test different shafts with our consumer groups and see which ones they prefer and the winner was the XP.