There are several size dependent actions I want to take as a city population grows, so I must look at the city size each time I visit that city. Easily seeing if a city size is 7 or 8 is difficult, 9 or 10 is painful, and 11 or 12 makes me curse the game each time I must count every one of those little people icons.
I guess I could enable a display to show the city size on the main map, but I prefer to keep all of those optional displays invisible. My wish is for the people display at the top left to have an indicator (space or dot or dash or asterisk) that separates each group or cluster of 4. Then instead of painfully counting PPPPPPPPPPP each time I visit that city, I can easily see how many there are in PPPP-PPPP-PPP.
