I tried the windshield film but the gamble didn't pay off for me. The first significant rock I took hit right near the top edge of the glass, which created a crack that started out as several inches, but since has doubled. Since the edges of glass are the most vulnerable, I'd rather have some kind of rubber edge protection than film across the glass.
The other issue with film is it makes managing your windshield cleanliness difficult. If you get any significant dirt or bugs on it, you really need to hand wash or hose wash it first or you risk scratching the film. On a road trip, we got a zillion bugs on it and scratched it while trying to clean them off at the gas station so we could actually see. The film cost me about 3x or more of my glass deductible, and I had it installed mostly because I had hoped to keep the original glass for as long as possible. Now that ship has sailed, I won't get it again, and knowing what I do now, probably would have saved the money. But each person's experience varies, and if mud, sand or bugs aren't common on your windshield, it may be worth the chance to you.