Currently I am reading the Aldis City sourcebook, and on the whole, I like it very, very much, chock-full of adventuring opportunities as it is.
But one niggling question remains: what is the geographical size of the city? Extrapolating from presumptions about river width and plaza sizes, I guesstimate the length and width of the city to be about 2,5 and 1,5 km or (1,5 and 1 miles), more or less.
Does this "guesstimate" make sense concerning population density? I am not sure.