When I first found this extension it had no reviews but I'm glad I took the chance and bought it.
The developer Thong was very helpful and responsive, assisting me with any troubleshooting such as getting the redirect syntax correct and fixing minor bugs.
So now it works perfectly and my link juice is saved. Massive redirects is extremely handy for migrating sites where the page urls are the same except for the suffix.
Especially with large sites it coudl save a lot of hassle by avoiding setting up individual 301s for each page.
It's working great in Joomla 3.2, give it a try!
EB is very intuitive and easy to use, has great features and the support is first rate. I submitted a support ticket to suggest an additional feature and within 2 days it was there, amazing. The only thing I can't get to work is the user integration where customers can log back in and check their order details. I think this will be getting fixed in the new version for Joomla 1.6 when it arrives.