According to the announcement, two main factors motivating the switch were calendar tools and having "modern" tools, which I interpret as having a better web-ba

According to the announcement, two main factors motivating the switch were calendar tools and having "modern" tools, which I interpret as having a better web-based UI. While Roundcube is OK, and personally I like Zimbra as the best turn-key system (webmail+calendar, which we use for our company), their UIs are a bit outdated and feel like second-class solutions.