I hit both Px and the 130s back before I went graphite. The 130s were much less harsh, pretty much the same performance from both, which is/was the best ball flight I could generate.
Unfortunately, for me, it was still too much on my elbow, so I’m exclusively graphite these days. The good part is it slows your hoeing right down when a new set of shafts runs $400. To be completely fair, about 10 swings with any steel shaft and I’m hurting, so don’t view my statement as saying they vibrate a lot, the Modus are REALLY smooth.
All that said the FST Pro shafts felt incredibly good as well and for a tiny fraction of the cost and not all that different in overall performance. I liken them much more to a KBS shaft, which is certainly different from the others, but “way more spin” from a steel shaft is not the same drastic difference as you can see in graphite, so as always ymmv, but in my experience, the difference in steel shafts wasn’t THAT great to justify the huge cost differences. That said, I had to try them all myself to believe so, do your thing.