Just to add to Laurie's post. You mentioned you modeled everything so you didn't have to "cheat" with a texture (I know not your words). But you seem to be mixing up bump maps with textures. I agree with Laurie. Your renders and fantastic and the modelling is exceptional but there's nothing there that really cries out "Look at me!". The plain solid gray of your models makes them neutral in the whole picture. At least add some lettering and decals. Use a more metallic texture. As I said above you don't HAVE to use the bump map channel to give the ships a more interesting texture and look. On another note, some people may not comment on your works even though technically they are great, but some people just aren't awed by this kind of art. What counts is how do YOU feel about your work? Are you doing it for yourself or just to get awes and ahs from the public? IOW what does your art mean to you?