The normal maps look dirty for some reason on the optimized one, like the mapped grooves have ragged edges instead of smooth ones (especially on the pods with the silvery things with 3 slots in them). Maybe it's a side effect of being so strong. Might also be that the normal map resolution isn't high enough. <-Ignore this. I looked at the OP instead of the normal map screenshots further down.
Also, for sure bring back the noise, but only if it doesn't look like trash if it's too low res. The slight sparkle is making the original look like metal, and the lack of sparkle is making the optimized one look like plastic.
Diffuse texture reduction is really noticeable, but probably only in the ship lab, since you won't have any of these filling up your whole screen in normal situations. 16% boost in performance is huge though, so kudos. As for color scheme, I don't have a personal preference as long as it fits in with the rest of the UEF fleet.