This was a huge step up from the official screen protector, which picked up a scratch from the dock immediately, and was a pain to remove finger prints from. It is rated at a very high hardness level, which time ought show if reflects durability. Putting it on was a good experience – I did it without any particles of dust, but a tiny tiny <1mm dot of air and the top left corner, over the bevel and not noticeable or interfering with the screen. Mine did not come with instructions.
My tips for application: Do it in a bathroom where you've had it steamy and the steam has just settled. This helps remove dust from the air. Line the protector over the screen and apply the included stickers to the bottom edge, overlapping onto the switch, so it is lined up and can clap down like a ‘hinge.’ After cleaning the switch with the alcohol/dry wipes, use the included tape to remove any visible smudges/dust. Then remove the back cover and allow the protector to fall down from the bottom up, smoothing out as you go upward to press it down. Leave to cure for a few hours at least before playing.