Anthony,
The most notable thing I see is lack of noise and damn good sensitivity. Star bloat and colour saturation loss with DSLRs with long subs is a problem to may DSLR users.
It's just the way the stars are smeared across a few pixels and the colour tends to appear at the edge of the star pixels, I see this a lot on my canon. They only way to fix this is lower sub time and more subs...maybe even higher ISO and shorter subs.
Given your low sub count, 2 subs, I suspect you'll get away with shorter subs on this target and indeed I must say this is a very tricky target to image....with low surface brightness and high brightness central coloured stars.
I can see your camera has already excelled and stand amazed!
Well done indeed.
