After extensive research we came to find that eTree supported placing users in multiple categories which was a requirement for the way our organization is setup. After a flawless install of the component, we had it up and running within minutes and couldn't be happier! An update was released and when we upgraded we had a single issue which the company addressed within a single day! They logged in, fixed the issue, told us what was wrong and that they were looking into preventing that issue in the future. What more could we ask for!? eTree has a very clean and well thought out interface, both for the end-users and the Joomla Administrator. It's truly a great product with most excellent support to back it up.