I don't usually take sides on issues like this, but it seems like everyone is offering opinions, not answers. To answer the question, YES, you can shoot +p and +p+ ammo from your Glock. BUT.....read your owners manual about waranty information regarding the use of such ammunition. If it breaks and the manufacturer finds out that you've been using out of recommendation ammo somehow, you're stuck with the repair bill or a very fancy paperweight!!
There is some debate as to if it will harm your gun. That depends on what condition that it is in to start with, how often and thuroughly you clean it, and how often you replace (or are willing to replace) things like recoil springs, etc. Look into wolf gunsprings if you plan on a steady diet of such ammo, and tune the pistol for it. This will help extend the life of it, but there can be no question that greater mechanical stress on a gun will eventually wear it out. It would appear on the surface that it will die sooner, but this all ties into spring tuning and regular maintenance. Any well tuned machine will break down if not maintained properly and in a timely manner.
As to the super man syndrome behind +p and +p+ ammo, (here's the opinion part!) it's mostly just bullet sales hype. Any well designed hollow point that feeds reliably and shoots accurately in your gun is what is best for it. Besides, it's relatively well established that hollow point bullets only show a MARKED expansion (in a perfect world) increase when accelerated above 1300fps, and even then only about 8% more diameter with only a marginal increase in penetration depth. Below that, it's all the same apples!
Use standard pressure factory cartridges and reloads, they're cheaper and just as good. Don't buy the hype in the gun rags.
Tom
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Remember, no matter where you go, there you are!