I'm thinking of ordering some of this stuff if it's really up ti 7°C better. I'll just have to check Amazon or eBay or somewhere else as no one is selling this in my country
But then i'm a bit afraid that i'll get the actual thing (at least for eBay)...
As for the damage, if you add diamond particles between two metals, it's logical that it will scratch it one way or another, even if they are all at specified 40 microns size. If there are so big particles to make dents half a milimeter big, then there has to be massive chunks of diamonds which you'd see during application of thermal compound imo. So it had to be something else.