The APEX DCAEK makes for a really sweet trigger, we have them on quite a few of our M&P40 pistols. We started adding individual parts as APEX was introducing them, and eventually switched over to installing kits. Even replacing professional trigger jobs with APEX kits.
More recently we've been installing their FSS trigger kits, with light triggers for competition (2 lbs. or so) and carry safe 4 1/2 lb. triggers in others. Once the polymer FSS trigger comes out, we may swap out the Aluminum FSS triggers in our carry firearms, but for competition I'll be sticking with the metal trigger.