The only problem with something like that is due to the lack of interior walls everything is rendered at once, and you have a lot of entities in there. Tis nicely made with interesting areas and views.
I remember making a map for Kingpin which was one big warehouse. Two teams had to fill their safes located at either end of the warehouse with cash. They could run into the middle where a hole in the roof allowed rain and cash to fall from the sky into a puddle below, or go right through to steal an opponents cash from their safe, meanwhile killing the other team who are trying to do the same... Good times.