While considerably more expensive, it is the easiest SP I've ever installed, fits perfectly, and unlike SP's that 'feel' and look similar to glass, this feels and looks exactly like glass because... it is. At less than .25mm thick, you really can't tell it's there. Surface hardness of 8H vs 2-3H on film protectors also adds a lot more protection, and unlike a film, it won't show the usual wear over time you see after a few months, there is no rainbow effect, and it should last the lifetime of your device (unless it does its job vs an impact).
I'm sure other tempered glass protectors will (or may already have) become available - this is just the only one that was available when I was looking to try one. That said, the quality/performance is so much better that I'll never go back to using a film protector again.