@Angultra. Thanks for posting. Version 1.5 only had two transition easing types (swing and linear), and it has two transition durations/speeds (fast and slow). Version 2.1 has 8 options for transition easing types and 3 options for transition duration/speeds. The mechanism for how the listing starts collapsed is the same for both versions. Both actually start out expanded and then collapses after the page loads. The earlier versions, prior to 2.0, used jQuery, but the current versions use Mootools.
What I would advise you to do is to adjust the values for the transition duration and the transition easing to produce similar results to the previous versions.