A big advantage for me was the thumbnails... and the reduction in bandwidth... because people no longer needed to view all the full size pictures. Now they can pick and choose.
Moderation (approval) before pics were live was a must for me as well.
Complete integration with threads so that there wasn't another username to deal with was important too.
I use it behind an iBill password.... so I try to minimize the amount of logins they have.
Hope to get something so that subscriptions to it could be automated through paypal... and use groups instead of .htaccess with iBill. Maybe after the first of the year.
