Redirection is a wonderful plugin and I use it a lot. However, as far as I can tell, it only redirects posts and pages, which is only part of what happens on a WordPress site.
From time to time, I merge terms (tags, mostly) or rename them and this requires manual action to redirect. It'd be great if Redirection could "keep an eye" on this too.
On some sites, I use the Media File Renamer plugin to optimise image file names after they are uploaded, which means that if an image file name is changed after it's been used in a published post, manual redirect action is required again. It'd be great if Redirection "hooked" into this action and redirected the image URL automatically.