I was an early adopter of The M&P .40 and it's my strong understanding that there are variations, even among the Gen 1 pistols, that prevent interchangeability of triggers and upgrades.
I know my pistol will not accept popular trigger upgrades that will work in later Gen 1 pistols.
That being said, my M&P .40 has been 100% reliable with all sorts of FMJ range ammunition as well as hollow points of various bullet weights, although I prefer 180 grain myself.
The trigger is mediocre but serviceable and the pistol provides good combat accuracy.
One more thing; regardless of how hard I've tried to initiate a limp wrist failure, it's been absolutely impossible to limp wrist the gun.
Check the striker because the first iterations were considered to be problematic due to breakage, and I'd just replace it in a used gun that's going to be used for self defense.
This is what an early model M&P .40 looks like, you can compare the frame details with yours.
Later models have a sort of square cutout blank in the frame for the thumb safety even if they don't have one.
Also note that all of the early production pistols look like they have a key lock, including the direction arrow on the frame, even those like mine that do not.
Again, if yours is an early production example, you'll be limited as to trigger upgrades.
From your picture, your pistol is a later production model than mine, but I'd check for compatibility before buying and trigger upgrades.