Overall, I'm a a fan, though I think perhaps I wouldn't have gone with cylindrical connectors on the long axis. I guess I can kinda see why you did it, but the concept art makes it pretty clear that these are supposed to be squared off. Moreover, I think they kind of make it look a little small - like those areas are single man sized corridors rather than big thick connectors they are on a seven hundred metre long ship.
The engines are nice though, and the greebling overall seems appropriate. I particularly like the second version of the front brace - the central column it has now makes logical sense and gives it a look of solidity and strength, like a proper structural support (and I know, that'd be largely useless in space, but the aesthetics are, I think, important).
