An update and a comment. As there has been a few posts about the Modus 105 vs 120 here was my experience. The 120 felt like the worst shaft I have ever hit. It felt terrible in my hands and very boardy. Manimal had explained why it felt that way to me in another post. I then went with the 105 S and much, much better for feel.
Played in Florida last weekend with my new JPX 919 F, Modus 105 S shafts. The 5-6 irons were a beast. Great flight and distance. The 5 iron has basically thrown my 25 degree hybrid out of the bag, they go the same distance but the 5 is more controlled on misses. I struggled with the mid irons, 7-9 and not sure why. Probably swing related but I think I am used to a more blade type of look and feel but I will argue against myself in the next sentence. The PW and Gap were right on and I could change distances and flights with these clubs.
I think the 105's are going to work out with this iron head. I came from T-100 so a little chunky but I expected that. What really amazed me was how I wasn't penalized a ton for a thin miss like I was with the T-100 but I'm sure that's expected. Just for a reference 6I SS for me is about 72 mph. I also release early which I hate but it's there!