Check out the Apex trigger pull on the Shield at the 10 minute 15 second time frame of this video:
M&P Shield Apex Trigger Install Results - YouTube
Using the stock Shield springs the trigger pull is 4.25 pounds.
Or check this video showing the same trigger with a trigger stop at 8 minutes 10 seconds:
http://youtu.be/b8TzoGDI3Iw
Trigger pull 3 pounds 10-12 ounces by using a Glock trigger spring.
I am sure I will get comments about that being an unsafe trigger for carry. Improvements to a gun, that allow you to shoot it better, make it a better carry gun. The lighter trigger pull and trigger stop, on my Shield, helps me shoot it more consistently and have faster recovery. People should practice shooting their carry gun, so they become used to the trigger pull, recoil and recovery, and can shoot it accurately. This is now my only carry gun and I don't have to worry about different trigger pulls between guns. What makes a safe carry gun is training and practice, and knowing your gun. Also if you follow proper gun safety rules, your finger should be off the trigger until you know your target and are ready to fire. The Shield has a manual safety. I carry with that safety on and practice flipping it off, with my thumb, as I draw my weapon. I also might have a better idea as to how I would react in a stress situation, as I spent many years in LE.
I would agree that a long, heavy trigger pull is what an inexperienced shooter should have. This would also apply to those that have experience, but fail to practice often with their carry gun.
RobsTV you have to clamp the slide in a vice and pound hard on the sight to get it off. You may have to heat the set screw to get it to loosen. Knock it off from left to right. It is pressed on at the factory and you have to pound hard to drive it off. Wrap your punch in tape to protect the sight from damage. I used only the Apex sear and blocker, not the kit.
I can somewhat agree that the Apex kit was not a dramatic change from the stock trigger pull. It shotrened the total sear, over travel, reset from 7/32 inch to 1/8 inch, or 3/32 inch less. Most of that was in over travel. What I liked best was the reduced trigger pull weight from 6.5 pounds to 4.25 pounds using the stock Shield springs. But with my over travel stop I now have a total sear, over travel, reset of just over 1/16 inch. Now that is a big improvement. If I had installed the over travel stop with the stock trigger, my total pull would have been 1/8 inch.
After the Apex install, I still had a gritty pull. I had to remove the blocker and grind a burr out of the blocker bore. See the following video how I did that:
http://youtu.be/6_r-J4zAJHo
Bob