Has anyone had a chance to test these shafts side by side and have any rough feedback on feel, ball flight etc?

I have the KBS in my Callaway X-Forged but am switching to my new MMB-17 for this season, but with their costs I am leaning towards the FST 125 Stepless to give me a similar MPF (lowering the shaft stiffness from X Soft Step 1) to possibly S+ in the FST.

I was on the PGA Tour Superstore launch monitor the previous weekend with both 6 irons and had a strong pull hook with the Callaway, draw/hook with the MMB’s but the overall specs were 180-200yds (swing speed varied between 89-99mph). I resolved the hook issue with midsize grips but would like to now build my MMB’s with midsize grips and the FST shaft.