Theres one flaw (at least I think it is a flaw, mabe others have a different play style): When I found a city late in the game because I want the resources and the terrain isn't that good otherwise I dont want the city grow quickly. It increases unhappiness and doesn't add much of value.
Trading post spam it and get some gold out of it
![Big Grin :D :D](/data/assets/smilies/biggrin.gif)