Well, up close it looks rough but I bet its a lot better farther away. Also you dont have to make stuff fit the model - you just draw it on the right shape and size to fit so that's a bonus.
I guess by the time you put the effort in to make the 3D object then you gotta think its worth putting the effort in for all the textures too. But that is a slow process.
With a dash of equally quick color and maybe 5 or 6 different style houses I bet that it would look quite good.