Um, who's doing the SSD again? I'm not catching who this GE guy is. You seemed to indicate that he was still working on the model, so no reason not to critique this time, I think. Still feel a little guilty about that bit about the TIEs.
About that, a few things.
1. There's some sort of differently textured block structure lodged in the trench between the prongs made by the dorsal/ventral hull plates, at the tip of the 'dagger'. What's that doing there? Get it out.
2. Why are you putting greeblies on the 'city'? Why waste time and polys with the little boxes and trenches when you could be making a better approximation of the overall geometry? I mean, first of all, the drop from the hull isn't deep or steep enough in places, and at points it should actually be perpendicular to its present slope. Then there's the aft, which should blend almost smoothly into the city. The fore part of the city should actually connect downwards into the hull. It's only the sides that are unconnected. The buildings in general are interconnected so fluidly that there are only a few points where separate buildings are justified, as opposed to a sort of mangled step-pyramid appearance. This step appearance is particularly noticible near the command tower.
3. Same as 2, but for the drive section. Too many polys wasted on random little blocks, not enough good geometry. The biggest thing is that the engines on this model are hull-centered. This is only really true for the aftmost central engine. The aftmost lateral engines are supposed to sort of stick out to the sides of the main hull, and the other ten engines protrude downward, in some cases with a long visible cylinder appearance instead of just having the nozzle apparent. Also, this section overall seems to lack, i don't know, bulk. It should be kind of puffy looking.