I like the Apex sear and DIY polish/rounding on the factory striker block on M&Ps that don't have the newest upgrades. I traded in my M&P9FS for a 45FS, popped the rear sight off with a delrin tipped punch and hammer, reversed a drill bit in a drill, taped the block down on the bit and spun it on coarse then fine sandpaper at the right angle. Both create a perfect duty/self defense trigger pull.