The jelly fish image above looks better than most renders I've seen, but it's main flaw is composition. I was discussing this with someone the other day when looking at renders of Probert's concept for the E-C. I kept wondering why the painting looked so much more solid than the render even though the geometry of the painting was irreconcilable in some ways.
I realized its because in the painting the ship is level. And in being level it has gravity and a sense of weight. In other words, it looks grounded. The render was at an off angle like the E-D is above which makes it look airy and light, like a kite floating in the breeze. It detracts from the mass of the vessel. Save the floaty angles for small ships and fighters. Capital ships should always be horizontally level.