Here's a break down:
DCAEK-"Duty/Carry Action Enhancement Kit"= utimate striker block w/spring (removes grit and smooths pull), hard sear w/spring (removes over travel, lowers pull weight, and slightly improves reset), duty/carry trigger return spring (raises trigger pull back up some to meet duty standards)
CompAEK-"Competetion Action Enhancement Kit"= utimate striker block w/spring (removes grit and smooths pull), hard sear w/spring (removes over travel, lowers pull weight, and slightly improves reset), lighter comp trigger return spring (further reduces pull), and comp striker spring (also reduces pull weight).
The Aluminum AEK trigger was designed to replace the stock hinged trigger if desired and can be used in conjunction with any combination of factory parts or the above kits but is not to be confused with the FSS which outwardly looks very similar.
RAM- "Reset Assist Mechanism"= an optional kit that "improves" tactile/audible trigger reset. If you are prefer a "Glockish" trigger, this will make you feel right at home. Coming from a Glock myself, I planned on installing one but never got around to it. After getting used to the platform, I no longer think the RAM is necessary.
FSS- "Front Set Sear"= completely different trigger group, springs and sear than and not compatable with the others. Totally changes the geometry of the pull and moves the break point much further forward with very little pre or over travel. Feels almost like a single action trigger. There are both aluminum and plastic versions of this trigger.
Hope this helps.
I have the FSS in my M&P for 3gun and love it. Apex also just released a flat trigger similar to the FSS - https://apextactical.com/store/product-info.php?pid87.htmlI have 2 with the FSS and wouldn't have it any other way.
This guy seems to have a decent understanding of Apex parts...
First, how old is your M&P? and what model?
The newer full sized and compacts manufactured in 2014 have the performance center sear in them, which in my opinion, is magnitudes better then the apex.
The apex trigger system has creep in it, or as they call it a "rolling break", which some like, but I prefer a crisp break.
If you want to try to lighten your pull first before installing apex, polish the rear sear face and striker block. It will drop your pull a lot.
Does the FFS kit put you in a different division for games like IDPA, USPSA and 3-gun?
Is the 2014 trigger not gritty? I have not tried any 2014.
Gritty trigger pull comes from an unpolished trigger bar hitting an unpolished striker block.
Can be fixed in 20 minutes with a polishing job, or you can spend 1000+ rounds and accomplish the same task.
I chose to polish it.
My 2012 full sized had the "false reset" as I called it, where the trigger bar would release the striker block before the actual reset. This was remedied with rounding and polishing the striker block. It sits at around 5lbs.
My 2014 compact had a VERY heavy trigger pull from the factory, to the point I thought it was one of the 10lb compliant guns. Initially measured at 7.5 lbs. After polishing the sear, striker block, and trigger bar it dropped to around 4.5 lbs.
Both have clean crisp breaks, no creep that I can feel, and very little over travel on the full sized because it has the old sear and s stamped trigger bar. I could probably remove this by adjusting the trigger bar loop, but it doesn't bother me.
How do they make the trigger bar now?
This guy seems to have a decent understanding of Apex parts...
So in my case I want a smoother, lighter pull with minimal grit and a new trigger face.
Would it be smarter to buy the FSS kit or to get the CompAEK + Aluminum AEK trigger?