GD bbPress Toolbox Pro started its life by merging 3 free plugins into one: GD bbPress Attachments, GD bbPress Tools, and GD bbPress Widgets. That happened in 2012. Since then, GD bbPress Toolbox Pro has gone through many versions and it is expanded with many new features that are not available in free plugins. It is hard to compare Free and Pro plugin, and you need to try Pro version to see how much different and better this plugin is.
A while back GD bbPress Widgets Free plugin have been retired, and now, GD bbPress Attachments and GD bbPress Tools combined have about 10% of the features available in GD bbPress Toolbox Pro. Pro plugin is quite a different plugin compared to free versions, and it is almost impossible to list the differences. Even the features available in Free plugins are significantly expanded in Pro.