I have used it for a month, developing a site, but found an issue with the data design that causes a limit. You cannot search for events based on geographic locations. You can search for events based on the name of the venue or date or category of event. This leads me to think the developers intended its use for a smaller scale, local environment. As is, if you get a 1000 events with distinct locations over the course of time, you will have a 1000 location drop down box to choose from when setting up new events. (Locations of events are global and put in a separate table, not tied to the event in the same table.)
When this issue is addressed, the component will be very valuable. You can integrate (somewhat, not all aspects of) RSForms Pro to get more data when people sign up. This is nice.
The component allows you to sell "tickets" to events (via paypal or 'wire transfer' - no one uses that in the USA) but the integration doesn't allow subscriptions or recurring payments.
This is a very affordable add-in if your site wants to have event listings and an events calendar. I recommend it. I think the improvements it needs will come over the course of time.