Leon,
Hey, no worries, I also have a Canon D5 and it spits out 4368 x 2912 images
so, as I am using independent server for my uploads, I suspect (having never tried an alternative) there must be an ISS limitation here.
That said..colours look great
Stars look like pin picks, good shadow detail and highlights (as best I can tell) look not to be burnt out.
This is good stuff !
Cheers
Peter