Columnav is definitely a cool widget when you have a small data set with not too many items for each column. Once the number of items grow to a certain size, the response time suffers. Introducing extra levels of clicks can only help to a certain extend before the users get confused or annoyed with the large/complex navigation tree. As a recommendation for a future release of columnav, how about adding a Predictive Fetch feature to columnav? This will allow the users to see an initial set of items immediately. When the user scrolls down the list, approaching the end of existing chunk, the widget fetches the next chunk, which enables the user to continue navigating with little wait.