I already have the 714 AP2's with the Project X Pxi 5-PW and AP1 3-4 iron ... but I hit the AP2 much more consistently than the AP1 for some reason.  So I was going to order the 3 & 4 iron to make the entire set AP2.
My question is would I see a considerable difference in the Project X Pxi vs the XP95 shaft??  Knowing that there is a $35 upcharge for the Project X and I am a little strapped for cash at the moment.  Would the XP95 help the long irons get more in the air??  I hope so.  
Any thoughts would be greatly appreciated .... before I take the plunge yet again.