Same balls, went from cavitys to progressive cavity. I got this from somebody else:

"Just because they are lighter does not necessarily mean they will go the same distance even if they were the same loft. Sometimes, the slightly heavier swing weight of the DG shafts allows us to make a better golf swing. When you go lighter you usually go through a transition period. The transition period lasts a while because you will tend to get over the top of a lighter iron where you were dropping your arms better in the downswing as a result of the heavier DG shafts."

The difference between the old Dynamic Gold steel shafts and the Apache MFS 40+ graphites is almost 40 grams, but he bumped the swingweight up. Maybe these shaft's are just a bit light for me.

I'll play with them for awhile and see what happens. If I'm not happy by the end of next spring I'll probally go back to steel shafts and split the difference weight wise between the 2 and see what happens..