Worledit is amazing as a mod. Given enough resources, anything is possible; a city can be built from a single skyscraper, but given enough laziness, things go ugly quickly.
My server is full of cities and "infrastructure" just like this.
Worldedit is such a powerful tool it can quickly destroy the charm of a server in the wrong hands, and that's what makes it so dangerous.
But in the right hands great things happen, and far quicker.