This is an absolutely awesome extension. Out of the box it overrides Joomla's default user management system, letting you add extra fields, allowing users to edit their profiles and upload avatars. Users can talk to each other via email and view each other's profiles. There are a huge number of lovely little touches, for example you can hide fieds when the user first registers so the user is not overwhelmed by a massive form.
Installation was easy but not trivial. A helpful readme file was included which took me through the process of publishing the correct modules and disabling the standard user login functionality. Overall, this is a very impressive piece of work and I'm looking forward to playing with it further!