I am wondering if there are any blog owners with larger blogs (1k+ articles) that are using a related article/post type plugin or have some kind of custom code to achieve the same thing. How do you guys go about it without killing the server?

I have not tried any yet but it seems as though most of these plugins query everything from title to tags to the actual content in the post. I have heard stories of people who plugged in these widgets and saw there total query time go from .3 seconds to 10+ seconds.

Any help is greatly appreciated.