It's a cool looking ship. A couple of thoughts though,

As something non-organic for your show reel it's pretty organic looking :), something a bit more square and chunky might be an idea?

IMHO the eye jerks a little on the rear engines/thrusters (not the ones underneath), The tail swoops down in a nice smooth way and the pipes just seem to stick out, as though they're not meant to be there. Maybe selecting polys at the back of the ship and extruding them inward a little to create a lip and a flat surface at the back that the thrusters then are mounted on?

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Toolset: Blender, GIMP, Indigo Render, LuxRender, TopMod, Knotplot, Ivy Gen, Plant Studio.