As it turns out though, SEO calls for slug based permalinks since search engines strongly favor pages with keywords in the URL. I decided to switch to date and slug based permalinks, but what about all the numbered archive/%post_id% links that have been posted, linked, bookmarked, indexed, etc.? Well I found this great WordPress plugin called Redirection. It lets you specify URLs you want redirected and what HTTP response code (301, 302, 307, 404) to use. It also features a log of redirects and 404 errors, so you can look for common requested URLs that don’t exist and redirect them. It would be kind of hard to update a few hundred links to the new slug URLs, but for 5 posts it was very simple and just what I needed. Another great feature is, anytime you edit a post slug it automatically adds a redirection rule to the new URL.