I've had great luck, so far, with the JCal component and modules. Easy installation and seamless transfer of events from ExtCal. The one odd thing that I can't seem to correct is that all events are listed with "MDT" following the date/time of the event, despite the fact that the time zone is set correctly in the admin back-end (Eastern Time). If I use a 24-hour option, no problem, but the 12-hour option results in something like this: "Date: Saturday, July 07, 2007 At 8:00:00 Am MDT".
I'd also like an option for a simple, default text editor, rather than providing the more robust editors for entering event information (stuff like "insert image" confuses the operation).
Minor quibbles, though. All in all, JCal is a fine component, and many thanks to the creators.