From all I've read... NEVER use +P+ in your P-11 and only rarely use +P.  You can test with it occasionally to ensure reliability and carry with +P for SF.  From what I've read, I like CorBonPow'rBall but I'll not shoot it very often. Besides, it's pricey stuff. You may need to switch to Wolff +10 recoil springs when shooting +P ammo to help soften the blow when the slide racks back and then switch back to standard springs when shooting standard ammo to avoid FTEject problems.