Bence-I know exactly what you mean about the silvery sheen you can get from some sealants. I really noticed it with Klasse SG on black. I thought I had pics of a BMW 740 I had done a few years back with SG on my computer, it really showed the effect very well-but I can't find the pics. 
I've noticed that with S100 as well.

I've noticed that with S100 as well.