To the north is a city composed entirely of manufacturing, high tech, and high wealth commercial, the east is a city composed entirely of manufacturing, dirty industry, and waste incineration plants, to the south is a small city composed of medium density low and medium wealth apartments, and to the west is a city composed entirely of high tech industry. All are running budget surpluses, some as high as 15k a month.
I'm currently saving up money for the subway system which will hopefully make those briefcases above some of the buildings go away - it's not an issue of there not being enough jobs but a transportation problem. The skyscrapers have such high populations that 1 or 2 will completely overwhelm a bus stop.
I think my next high density city will probably use a much denser street grid so I fit two skyscrapers to a block along with a bus/sub/rail connection.
I may also move the airport to a lower density city.
