I am playing AP2 irons with PX 5.5. I'm considering re-shafting to a light slightly more flexible shaft but wonder how it will effect the playability of my irons.
In some cases, the lighter the shaft you switch to, the higher the ball flight/spin can get. This is the case with many shafts, but not all. The PXi has similar characteristics (kick point/spin) to the original Project X, but is close to 10 grams lighter. This is a good option to consider if you like the Project X, but just want something lighter.