You should only age stuff that meant to be old.

So I didn't mind the Naboo ships and the Senate looking clean and new.

If anything some of the PT stuff is inappropriately aged, the senate craft and the Jedi ships are maintained by a Government that has access to most of the Galaxy's top technicians and engineers.

Their stuff should look new even when it's ancient.

On Tatooine everything should look beaten up and worn out and it does.

It would have been nice to see Coruscant and the Naboo etc losing it's shine as the war went on because they are having to make do and mend because they have less resources.

It would also be nice to see the capital damaged by the battles.

Theed and Coruscant don't look like they have been in a war at all in the end of ROTS.