I have been testing auto tags plug-ins and duplicate materials a couple of days ago and they are really bad for your website. It is definitely confirmed. I have two similar blogs but different niches and tested auto tags plugin and duplicate materials for a couple of months.

Google discount the fact the entries that are similar to one another even though it is actually not a content but a reminder and disclaimer sort. But still Google has been no longer indexing pages with no unique content in it. This is not a read and write experience. I have been testing all the SEO techniques mostly all on my own and this is really an important factors for all newbies, SEO and SEM analysts..

so, hope this helps.