You can't go wrong with the DCAEK kit.
My M & P 45C before was well over 9 lbs had a very gritty trigger. Dry fired it several hundred times and shot about three hundred rds ........ trigger still felt the same the pull was the same grit feeling was still there.
I put the APEX full carry kit in, it dropped the pull to 5.25 lbs grit was totally done and the reset is much more noticeable.
I carry it CC in a Crossbread Super tuck and have total confidence. I do carry the SW 642 in a Supertuck also it is a lot lighter and is more comfortable to carry. But when I do carry the 45C I have total confidence that a ND will not happen.
The difference the kit will make in the feel of the trgger will shock you.
My experience anyway.
Dan