I think this is one of the best calendar plugins around if not the best. its simple to use and just works. Its well spec'd with things like Google map locations, event cost and so much more. The best way to understand this great plugin is to install it and use it.
Two options I'd like to see are events backup, and in the Event Date and Time section an option for "To Be Arranged" (TBA) as some of the events I have to add aren't always a firm date, so what I end up doing is adding an approximate date instead which isn't really acceptable.
I am so glad I didn't update this plugin, as of now I'm still on 1.8.4 Premium and everything is working fine. I see a lot of people trying to find the 1.8.4 version, I've uploaded versions 1.8.4, 1.8.3 and 1.8.1 if you need the plugin: Mediafire AI1EC
One thing I would really like to know is how to remove the update banner because until I see some favourable reviews of 1.9.x I won't be updating.