Hello everybody, long time browser with very little posts. I usually have no need to comment, but I felt like I need to throw some of my opinions out there. These are only my opinions and I feel that I'm not an expert, but do have some experience in this subject.
Like others have said, if you are involved in a shooting, good or bad, you may or may not be sued. Being sued is NOT a sure thing.
If you are involved in a good (justified) shooting, and you altered your pistol, and you are getting sued for it. You were probably going to get sued for something anyway. The altering is just another area to be attacked.
If you are involved in a bad shooting, whether or not you altered your pistol, you are f-ed.
I like to think of it this way...If altering of the pistol increases performance, and is still safe/reliable, go for it. Just be prepared to explain your reasons if that day comes. Be articulate, be realistic. There is no need to make a trigger on an MP carry pistol 3 pounds. But if you want to add apex parts, lighten it some, and make it a smooth reliable pull, I'm all for it.
For most LEO and CCW carrying citizens, a factory recent made MP trigger that's been fired and broken in, is probably fine. I prefer the Apex sear and ultimate striker block. It lightens up the trigger some and makes it smoother. I have only been carrying the MP pistol since last summer, but a daily basis, all day/night long. It has 6 thousand rounds through it since June 2013. Most of those rounds have been with an Apex sear. The only issues were ammo related, on a single day in August, with ammo that shouldn't of even been used. Zero malfunctions besides that.
For most people, I would rather see them shoot and learn the pistol, break it in, and get some training, before making alterations to it. Figure out what you really need and what you don't.
Once again, these are only my opinions and hopefully it makes sense to the readers here.
By the way, I'm in my 15th year as an LEO, a majority of my career has been spent in plain clothes/undercover assignments. I'm one of my departments firearms instructors and an MP armorer.
I have been in numerous shootings where I was either the Officer or the witness to another Officer discharging their pistol. I can tell you for a fact, that in my involvement, I was never even asked about alterations to my pistol. I was asked a lot of other questions, tactics, number of rounds in magazine, etc. Luckily the shootings were justified. If they were not, like I said above, you are still f-ed whether or not the pistol is altered. Probably more f-ed if you had lightened up the trigger and had harmed somebody by accident.
Altering the pistol and possibly being scrutinized for it and/or sued at a later time is a risk I'm wiling to take. I feel the alternations allow me to shoot very slightly more accurate, which may or may not save my life or someone else's.
Thank You