Steel Fiber or Recoil

Would love to hear some feedback on anyone's opinions of the Steel Fiber shafts vs the Recoil shafts for Irons. I'm pretty dead set on installing graphite into my irons.(Getting older, and to help with the golfers elbow)I have had the chance to hit them indoors in a simulator but not in any of the new Titleist heads. Plan on going to get fitted when the weather permits, but just wanted to hear some others thoughts. Has anyone had the chance or currently playing them in Titleist heads? I have been playing DG300 for as long as I can remember...