I preferred Asus blue setup as I like the color but this is cool to have a matching setup if you have to do that.
Had a guy at my work who had a HD7970 and everything was red (even his power cables) and when he bought a Titan he switched to green for everything (including motherboard and CPU fans for his Noctua).
I guess if you want to show off its cool and I understand as for my P8Z68-V Pro Gen 3 I have black Corsair vengeance for the black slots and blue for the blue slots. Just looks nicer.
I think EK should do this on all their waterblocks. I don't really give a crap what it looks like, but gold is highly corrosion resistant.
It is slow to oxidise, but how much better is it than the more common alloys they use? I believe it is generally cheaper to have the nickel, copper thing they normally have but has a similar effectiveness and oxidation rate as the gold.
Edit: as it turns out they probably don't use alloys, but plating. So gold would be a nice alternative to those who desire a long living cooling block 😛 .