I have a m&p shield in 9mm, a m&p 22, m&p 45 and just picked up a m&p 9 with an apex trigger job on it. The apex trigger job is definitely lighter than the stock trigger. I will put the apex trigger on my 45 but I don't think I will put it on my edc shield. To me there is a noticeable difference in trigger pull. The apex is much lighter and may be a little more sensitive than the stock trigger. This is something that I don't think is necessary on a carry gun.