I just installed mine yesterday. Not the easiest task. Wish I could have done it a lil more neater. I ran out of the spray, i just substituted with "Diamond" water. Works no problem also.

I think when i reposition the back part, the adhesive caught some fine dust. But i am not gonna risk taking out the whole thing just for one small part which doesn't look fine.

Some fine scratches on the original backing has also been hidden by the invisibleshield.

The one I got, the front wasn't well cut. The earpiece hole was higher than the actual earpiece on the iphone. Maybe i stretched it too much? But luckily, still got a hole for me to listen through the earpiece.

Wish, they could improve the design, and make it even a better fit for the iphone, with really "full" coverage around the edges.

I tried scratching with a key... no scratches...

But....

I was "lucky" enough to get a fine scratch because i think i used the sharp edge of the key near the edge.

So... good for scratches not cuts...

I too adventurous edi... go and test myself... :-p

Since I am in the USA. I contacted ZAGG customer service for a replacement. It took less than a week for them to send me a new one.