Redirection works fine for what it is intended to do. I was using it because I ported a site from another management system that did not use slugnames and needed specific pages to be redirected to the new ones in wordpress.
The problem is I'm using custom post types now for some parts of that site and if a person goes to an old wordpress url that has been moved to a custom post type with it's own custom permalink name it throws a redirection loop error. For example if a person goes to the old url domain.com/2012/4/22/slugname which is now domain.com/customname/slugname the redirection loop occurs. I haven't tried putting the old url in redirection plugin because wordpress already redirects urls to the new based on the slugname.
When the redirection plugin is turned off, the old URL goes to the new custom post type URL just fine.