I got some reccomendations here, but I don't want to sound like I'm being negative. I like a lot of this so far... so, take this in a positive spirit.
Tweak the color of the lettering. Solid black never looks quite right, so try something like R:16, G:16, B:32. It may seem like a subtle difference, but it really helps make the model look more 'real'.
Lower the impulse intake grills to be only
slightly above the hull. They're not stand-out boxes. Right now the elevation detracts from the smooth look of the hull.
Similarly, soften the red a bit from absolute and mix some gull grey into the color. The red is too sharp as it is, making it look a little 'cartoony'. (This is most obvious on the markings near the impulse intakes... which are actually yellow, not red).
The linear accelerator should also be the same color as the impulse engines themselves. This will help break up the look of the primary hull as well.
In contrast to the red, use a less matte finish on the copper. Right now it's a bit too 'flat' and comes off a bit too much like plastic. The 'spike' on the dish should also be gun-silver, not copper.
Hope this helps, and look forward to seeing more.
