I have littlr use for +P+ and +P.
My only uses for it are:
1. +P+ 38 special in a 357 magnum revolver. K frame guns are easier to control.
2. +P in K frame size 38 special revolvers.
Never use either in a semiautomatic. They are built for a specific pressure range. There are those that will tell you it's okay if you use a heavier recoil spring.
They know more than the engineers that designed the gun? The recoil spring has nothing to do containing pressure. These heavy loads will accelerate wear.
Once you have created an entrance and exit wound in the target there's nothing that extra velocity dies.
+P and +P+ do little, if anything to improve terminal ballistics.