Sounds like if your swing is solid and your leaving it out there, moving to S400's could help you out.   But, you can never go wrong with a fitting by someone who really know'a there stuff.

Hi Jason,

I see you have the Diamana S in your 913's. This shaft is know for having a mid to high ball flight compared to other stock options. But you say you "baby" it and produce a low ball flight. I have friend that has a 113 mph swing speed average and he has tried my Diamana kai'li. It is still intact, no baby swing needed. He can produce an incredibly higher ball flight with it than I can. Also, if you are looking to increase ball flight, generally going lighter in mass will get you that result. Going to an X-flex usually entails going higher in mass.

I think you might simply benefit from a shaft with a different bend profile so you have a more solid feel during the swing. That way you can mentally trust that you can unleash a full swing that you don't "baby". Maybe even try a shaft that has lower launch and less spin but offset that by adding loft.

Iron shaft wise, is your miss a push or a fade? Might be something that can be corrected with a lesson since your clubs are already 2 degrees upright and lengthened. The S400 and X100 are similar in weight, so I don't think you will see much change in performance as much as feel.

Bottom line though, something doesn't seem to add up with that swing speed and club set up producing a low flight, so you should probably schedule an in depth fitting appointment or maybe even lessons.