I've heard of Opticoat and CQuartz, but not so much Gtechniq. Found a series of pictures from someone who tested it out and you can get an idea of what it'd look like fully cured.
Initial Impressions & Application: Gtechniq Crystal Serum Light (CSL) | Ask a Pro Blog
Initial Impressions & Application: Gtechniq Crystal Serum Light (CSL) | Ask a Pro Blog