I am also currently using S300's, but have been thinking of Project X or KBS for my next set. I love the feel of the KBS but slightly prefer the lower ball flight of the S300's........good luck with your decision and I look forward to your review.

I used to be a diehard DG S300 user, but in my current set (Titleist Z Blends), I elected to go with project x after hitting a bucket of them at demo days.  I then ordered the irons with Proj X "Flighted" - The flighted option keeps the trajectory of the short irons lower and the long irons a higher trajectory.  I am a believer.  I feel my long irons are the best they ever have been, flying high and landing soft, not to mention added distance due to the higher trajectory.  My short irons dont seem to me to fly any lower than they used to, but not a big deal for me.  And the shaft just seems smoother to me as well.

Give 'em a try.

Rob

I am curious to compare the KBS and Project X in the AP2 to see which one is the best fit for me.

I have the Dynamic Gold SLs in mine.  I like the lighter weight but same solid feel as the original DG shaft.