Hi Matt, 

Thanks for the post. 

When it comes to changing iron shafts, it is important to identify what you would like to see improve with your iron flight. Do you hit your current irons too high, too low, left, right? If you are currently hitting your irons well (which it sounds like you are), I would be hesitant to change shafts because you have heard good things about another shaft. 

The best way to determine if a shaft is right for you is to see a local fitter and actually try the shaft.

I hope this information helps.

Bubba

Matt, 

i have played the project X 5.5 shafts on some Callys and i thought i would never use anything else.  My current irons have the KBS tour shafts and WOW!  If you are considering purchasing some shafts i would definitely give KBS a try.  hope this helps

-Billy

I've played Project X shafts for a number of years now and will say this, try them before you commit to a set in all of your irons and wedges.  You're either going to absolutely love them or absolutely hate them.  There isn't a lot of middle ground.  I like the Project X shafts, but since I'm not getting to play as much golf as I once did, I'm moving to KBS for a less harsh feel on those days when I'm not swinging 100%.  If you play a lot of golf, load the shaft pretty well and have a late release, Project X may be a great option for you.  Also, it's been my experience that they play about a flex firmer than the old Royal Precision Rifles that I played many, many moons ago back in high school.