As always, there is against the GGS glass nothing to say. The application is very easy. Even replace and again to correct possible. Bubbles can be much better and easier than with avoiding normal films with the glass. It is supplied with a shoulder screen protection. This, however, is bonded only at the edge - but that experience has shown that holds also very good.
The GGS glass can be had later easily removed again (after years). I had such a glass on my D600 and it was a breeze to remove it without residue.
Attention: The delivery takes a little longer, since the product comes from China.