Both have about the same torque and weight. The AMT is listed as mid-high and the KBS as low-mid launch. These are only guidelines. I found the AMT-Red launches higher for me than the AMC graphite that is listed as a high launch. Best to work with a fitter to see which one matches your game best. The AMTs have a variable weight based on the iron, so you may want to also try the AMT Black if the Red is too high of a launch.

I recently purchased the ap1 with amt red shafts and even with lower lofts than my old irons they launch high...but as Justin Thomas recently said "high and far ain't bad"! Seriously though they play well, I played in 20+ mph winds over the weekend and shot even par (a little better than I normally shoot), they don't balloon in the wind they seem to cut through it if you take an extra club, with my old irons if you didn't hit a knockdown it wasn't getting there in those winds even if you took 3 extra clubs!

Thanks for the answers!

I am pleased with the AMT Red S300 shafts in the AP1.

My previous clubs were TM M2's with the Reax shaft, and I never could quite get used to the superlight (88g) shafts. My clubs prior to those were Titleist DCI's. with the old MS209 Dynamic shafts.

The AMT Red S300 feels much more comfortable and solid. While I did not get fitted, I do feel these are the correct shaft for me. I am already more comfortable after 27 holes with the AP1's than I ever was with the M2's.