I had a free day in London and did my best to put it to good use with the D800.
Thought I'd have a look around the Imperial War Museum which was interesting, but stopped too many times for photos and so didn't have very much time there.
One thing that has particularly impressed me with the D800 is the Dynamic Range. I get plenty of detail where with the 5D mk III I have to rescue detail from the shadows which then produces lots of chroma noise. No such issue with the D800:
These are all around Westminster Bridge:
Nikon D800 14 - 24 at f/11 and 22mm 1/50 ISO 100 both converted in Silver efex