Jason,
I just received my custom fitted Mizuno Pro 225 (“225”).
All the clubs I tested were very good, but the 225 provided tighter dispersion and were longer over the others and over my current irons - Mizuno MP57 (“MP57”).
The 225s are also relatively more forgiving than the MP57. The fact that they are longer is not surprising since the MP57 are player irons and have softer lofts versus the 225s that are categorized as player distance irons. Also, the cumulative technological changes over 15 years since the release of my MP57 may have contributed to both the forgiveness and distance improvements.
My experience of more forgiveness over my replacement irons may be different than yours. You say that you are currently playing JPX919 (“919”) but what type do you have - “Tour”, “Forged” or “Hot Metal”?
As you may know, the “Tour” line is a players iron versus the game improvement line of the Hot Metal. Therefore, depending upon which 919 line you have would impact the amount of forgiveness improvement you would experience, if any, by making the change to the 225.
If you do decide to make the switch, you may want to hold off your purchase and consider the new release of the 225 successor that may occur either later this year or early next year (assuming the typical two year shelf life of Mizuno irons holds true). Alternatively if you really want the current 225, you may get them later this year at a discount as they may be phased out.
Also, not knowing the length of your golf season and assuming you will be fitted (I highly recommend), the turnaround time for custom ordered Mizuno irons may be 6 weeks or longer and that may cut into your golf season. So why not wait and either get the successor irons to the 225 or get the current 225 at a discount? Before considering this approach, you may want to confirm that the release of the new version of the 225 is imminent.
In summary, I don’t know your experience with your 919 irons, but for me the 225 irons are more forgiving than their sleek appearance would suggest and the ball flies off the club face for more distance versus my old irons.
I hope this helps.
Good luck.