As a new Joomla! user, I was excited to see an extension that would do exactly what I needed AND free. The configuration only took a few minutes and I didn't have to set up any additional folders or archives. I really like the feature of allowing the members to create their own categories while uploading images.
Easy to set up!
Easy to configure!
Lots of important features (i.e. disable image downloads, disable right clicks on images, etc.)
The "watermark" - Only because I like the ability to adjust size, color, opacity, etc. without having to create a new watermark to replace it.