Have you hit both clubs, side by side either on the course or simulator? Obviously feel is important, but so is club speed, launch angle, sidespin, etc.. Before making a decision (especially spending the extra to upgrade the shafts), I would compare them on the simulator where you can get some numbers. You may be able to get away with the stock shaft after the comparison if you are stuck on these two sets.
I'm sure though you are probably testing with steel shafts, right?