I have purchased AEC a while back for a client, and have had to re-use it recently, way after my actual support membership was expired. Nonetheless, the developer responded promptly, and provided guidance on a few requests I had, at no cost to my company. The component itself is a great piece of work, very, very large array of possible uses. While it does require some patience on its first use, it is a positive "problem" as that is due to the very vast amount of options. For those unsure whether it is worth paying for a component, any component, think again. This one does a great job, and you won't find anything similar on Joomla. The included support will save you loads of time sorting through all the possibilities, and the fast responses allow to continue working without hindering your deadlines, so props to David for that!