My iPhone (4S) has been dropped numerous times, and it has a number of small chips along the edges of the front glass – and as I have ruined several Invisible Shield protectors I decided to try one of the new glass screen protectors – as it says in the ads:
SPIGEN SGP’s Steinheil GLAS.t is made to protect the LCD from damage and scratches with specially processed glass that has been reinforced to increase shock absorbency.The entire surface of the GLAS t is transparent and the back side is covered with a strong silicon adhesive for easy installation. When installed, there are no gaps between the LCD and the GLAS t which means the touch screen’s sensitivity is unaffected. To prevent any excess force from coming in contact with the edges of the screen protector we highly recommend that a case is used with the GLAS.t.
* As this is a glass product, please note that the edges of the glass are the most vulnerable areas. We highly recommend that you use case along with your GLAS.t to avoid chipping or cracking the edges of your GLAS.t.
[From iPhone 4 / 4S Screen Protector GLAS.t Premium Tempered Glass Series | SPIGEN SGP]
Notice the “Caution” bit – it seems like a bit of a downside.
But on the upside – it is really “better than invisible” on the iPhone, as it actually is a lot more resistant to fingermarks, and so thin that I can use it with my normal iPhone case.