+P is fine for just about every modern pistol, and generally the ones that aren't are good about letting you know in the manual, or will not be marked +P (revolvers).
Glocks are just fine with +P loads.
Your STI and XD both are good with +P. If you plan to run a solid diet of +P through a 1911 then you'd probably want to install a frame buffer (at minimum), or increase the recoil spring weight to reduce frame battering. Especially if you have an aluminum frame 1911 since it is considerably softer than the steel slide.
Glocks, XDs, etc. are all polymer frame which absorbs alot of the shock from the slide. They don't need any modifications for a steady diet of +P