I keep my phones for exactly one year as I've been doing for quite some time with trade ins and now the Apple upgrade program.
And for that year I want the screen looking pristine every time I clean it with a micro fiber cloth. I've used em all over the last few years, anti glare, glass, full screen, etc etc.
Best screen protector I've used in the last few years is the Belkin Glass screen from apple. They put it on with the machine and honestly you can't even tell it's there. No dust, no air bubbles, no hassles of putting it on and worrying about any of those things. Yes it's $40 for the glass, but if I can't spend another $40 to protect my very expensive phone, I shouldn't be buying this very expensive phone in the first place.
Yes some will complain, hey it's up to you how you spend your money, and up to me how I spend mine. If someone is cool with a $10 screen protector off amazon, and is ok with dealing with putting it on...high five and good luck.