Cap2-mercurial is a plugin for Capistrano 2.x that enables developers to incorporate Mercurial into their recipes.
While the module is included in Capistrano, this particular project offers the latest updates and additional recipes that can make your life easier. For example, you may be able to save time and effort by using some of the built-in recipes instead of manually writing out each step of your deployment.
In terms of updates, the most recent release (at the time of this review) is reasonably reliable when used with cap2 and Mercurial 0.9.x. Of course, performance and compatibility may vary depending on your specific setup.
Overall, if you need a tool to help you integrate Mercurial into your Capistrano workflow, cap2-mercurial is definitely worth checking out. While it may not be a perfect fit for every user, it offers a useful set of features that could save you time and effort.
Version 0.9 RC2: N/A