I'm a big fan of GGS, even more so when it saved my S5's butt. I've used a GGS LCD protector on all my cameras whenever there is one available. For the D600 I held off on buying one for the D800 because the D600 and D800 use different parts for the Nikon plastic screen protector so I thought that their screens might be different too. Anyway, I found a GGS protector for the D600 on ebay and it finally got here yesterday.
Unlike my previous GGS protectors, this one is only for the main LCD screen (it did not include a protector for the top LCD). Bummer. I might look for a GGS protector for another camera with a similar sized top LCD to use its top LCD protector.
This GGS protector is the adhesive type, not the newer version III that clips over the LCD. It appears similar in construction to the other GGS protectors I've used.
The protector is very close to the actual shape of my D600's LCD though it's just a tiny bit wider.
GGS III Review
Nikon D600 Resource Page (see under "Accessories")