The model is fantastic! But, I must comment on the composting... whatever method you are using to isolate the ship from the background is sloppy. The edges are too soft. I don't know what software you are using but if there's some way to use a selection tool of some sort to make the edges sharper before cutting out the ship, that would make all the difference. Looks like you are taking a soft edge brush and are just painting out the background by hand.
But that's the only problem I can see. Elsewise, this looks wonderful!