I was slightly skeptical, given the cheap price, but this does exactly what it says on the tin. It feels exactly like the actual iPhone screen-- much nicer than the feel of plastic screen protectors.
It doesn't come with any instructions, but if you go to your favorite video site and search for "hinge method screen protector," you can find a screen installation method that works very well.
My two complaints (which may be inherent to all glass screen protectors):
• It's a bit heavier than a plastic screen protector. Not a big deal, but does add a subtly noticeable weight to my phone.
• It's a bit thicker than a plastic screen protector. Again, not a big deal, but when you look at the hole for the home button, you can see a little bit of depth.
Despite these minor complaints, I definitely prefer this to a plastic screen protector. Given how cheap it is, it's well worth taking a flyer on it and seeing if you agree.