Carry gun and modifications....
I have a S&W M&P Pro Series 9mm. The trigger was very good when I purchased it new, but does have a longer take up than my 1911 triggers. I would have no problem using this gun with +P JHP ammo for self defense.
However, the .357 SIG round is pretty stout, and using a polymer framed compact gun would most likely cause a great deal of muzzle flip....which does not help when trying to shoot fast follow up shots..... When using medium bore calibers with stout recoil, the heavier the gun, the better the recoil control.
My EDC gun is a .38 super, all steel Commander. I like and use 125 gr. Speer Gold Dot JHP bullets, that leave the muzzle at 1,350 fps. This may not have the velocity of the .357 SIG, but it is still a powerful and accurate round in my gun. I built the gun with a W/N ramped Bar Sto Bull barrel. The additional weight of the steel frame gun helps to mitigate recoil when compared to a stout load in the S&W M&P, and allows decent split times on follow up shots. I have no problem carrying it all day with an OWB holster. I like and prefer a 2.75# - 3# 1911 trigger with a clean break and no creep on my EDC gun.....this allows me optimal trigger control and greater accuracy when shooting fast....
I would say that in most states, in a self defense situation, the use of lethal force may be necessary if someone places you in fear for your life or the lives of others.....the type of weapon usually doesn't matter as much as the reason why you felt you had to use lethal force......if you have to save your life by using a baseball bat, it all depends on why you felt you needed to use lethal force to begin with.....which may have to be explained if it ever ends up in a trial. However, I know a very clear cut self defense shooting, where the victim felt the need to use lethal force, may not even be prosecuted if all the evidence points that it was a good self defense shoot.....otherwise, it may go to trial.
A self defense situation at an Orlando convenience store one evening happened several years ago. A 21 year old man was getting gas for his truck, when he heard screams coming from inside the convenience store....he witnessed a big man savagely beating a female store clerk. He got a handgun out of his truck and went to investigate. He told the man to stop beating the women, but the irate attacker turned on the smaller young man and said he was going to kill him..... The 21 year old shot and killed the man. When the police investigated, the whole scene was on video, and corroborated both the badly beaten woman's story and the young man that shot the attacker. It seems the irate attacker was the former boyfriend of the female store clerk, and was irate that she broke up with him...... the 21 year old man was taken into custody to explain the details and sign a sworn statement, but never spent a day in jail.......the DA did not bother to attempt to prosecute since it was a clear case of self defense...... The female store clerk also filed a statement and swore her former boyfriend had threatened her life several times, and felt he would have killed her if the young man had not intervened......she was taken by ambulance to a hospital for her injuries, but fully recovered.