COW seems to me to be a place limited only by one's imagination. Words on the computer screen can be transformed into vast empires that reflect the user's creativity. Even simple conversations between players seem to have more depth in COW than in other collaborative environments.
I find myself having to adjust to the increased level of contol and expression available to me. There are many hidden complexities here that take time to explore, but the friendly, communal nature of such an environment makes learning these a fairly enjoyable process.