Aah, well for one thing, it adds another tab to the menu, which is not good for those whose menu already wraps around (small screens).
But I'll leave it activated for awhile, so people can test if they want.
Note that as far as posting events, you can have a topic for that event started in any board that you choose. Whichever one is most appropriate. And another possibility would be to create a special board for holding, for example, only meeting announcments. Something like that.
Edit
If we decide to keep the big calendar, I'll probably get rid of the mini calendar. Because it does not give any indication about posted events.