[Suggestion] Larger Cities
I have one issue with large cities is that I can't build it anymore at level 5. With my capital city I get to my level 5 of the Town and nothing. Who in their right mind wouldn't build a castle, fort or just a wall around their capital or any other large city.
So in the end I suggest once a city reaches level 5 in one of the city trees that they can expand into one of the other trees allowing the city to develop further...and look more awesome.