I can't say much. The only reason I am interested in tinkering is I have a M&P 40c for carry now. I have a combination of glock/wolf springs coming Monday to see what I can do. I too was thinking of the trigger bar and have figured one thing out. With the trigger safety the way it is there is not much slack that can be taken out of it. I made a template of the current bar and then took a piece of 1/16 plastic and made quick mock up. You can take about 1/8" out of the pull before it get's to short to let the safety tuck. I also took the slack out of where it meets the seer assembly. I then realized it isn't worth 1/8 of an inch of pull for what it would cost to laser cut it out of stainless and tinker with it to get it better. I did polish the seer assembly inside and out and all surfaces. I also found a spring in an old box of misc that I then trimmed for the seer return. Between the polishing and the spring it is night and day.