We've used the free and premium versions on oodles of websites. It's our must have plugin for clients who want an event calendar. From multi-site websites for small businesses to a stand alone website for a big ten university, the plugin is easy to load and configure. Best of all, my clients are thrilled with the functionality and ease of use.
Due to the solid functionality and ease of use, I always recommend it to our custom design clients and the buyers of our premium Genesis themes.