Hmm, I see what you mean as far as the simplicity of the design. As far as how the thing would actually work, that's something I didn't even really think about. (as in, where does this thing "live", how does it move, how big is it compared to the pilot, how do you get in/out of the cockpit.)
Every time I make a drawing like this the designs make a little more sense. I'll just have to take some of those consideration in at the start next time I make a doodle.
(Thinking about this a little more, I guess my rendering isn't necessarily "concept art" in that the concept is bound up in just making the rendering look good.)
Anyway you could always do as you're doing right now, let the design go freely and then use it as a starting point for all the upgrades to the concept. Anyway i was talking about the design itself when i told you that stuff about grounded, it's not more like how it works but it's more "we human being did this?" at this point of the concept.
Much better than the first one but what's going on with that highlight reflection on the cockpit? I can't read it very well but doesn't seem to be ok to me. Anyway beside that thing if this ship is specular you forgot a piece of the engine from the other side, you should see a tiny portion of the big round part.
Oh yeah, don't use such a high saturation background because is flattening the ship rendering.