No problems installing or implementing the calendar. It does have one major limitation, IMO. Though it offers a flat view (ie list of events) it only shows events for the month being viewed. Therefore, if you're near the end of the month and have an important event coming up the following week (which falls in the next month) it simply doesn't show unless the user chooses to click on the next month. And from replies by the admin of their forum, it would be a major endeavor to hack the code to change this. So for site that have infrequent events scheduled in the calendar, this poses a problem.
There is a module and a bot that lists latest events regardless of month, so that can be done in a side bar. But if you want to have a link from the menu to the component, you end up with the problem above.
Otherwise, if you have frequent events, seems like a good enough calendar.