I'd maybe ask if you already own MP's and are familiar with them giving you a general pro and con list to start with?
What model are you looking at, as there can be a wide range of features available, even triggers will vary based on model.
I have a full size MP, trigger is obviously not the same as my PC Shield but i do just fine with it accuracy wise (for me). So i left mine all stock. Others like to change theirs.
Guess once you have your new gun in hand run some ammo thru it and make some decisions based on what you experienced first hand.