In my opinion, it would have been an excellent plugin, if not for its layout, which is a table-div-inline-CSS hell.
To give you just one example, in order to separate a couple of buttons by 5 px, the author placed them in a table, put a div between them, and set the width of that div to 5px, instead of just using a margin. There are divs within spans within divs within table cells within divs all over the place.
And you better make sure you have enough Timezones, and your "magic quotes" disabled, otherwise the plugin will remind you of your shortcomings on every page of your admin panel (!) with huge banners, that will push your useful content half the browser window height down, until you find the way to disable them.
There are some glitches, for example, jGrowl pop-ups "Loading events... " sometimes just remain there after the events has loaded (I had to set the opacity to 0 for the entire container div, to hide the damn thing completely).
All that said, I'd like to confirm that the plugin offers decent functionality with lots of options. If not for its layout, I'd probably rate it five stars.