thank you for your reply, I appreciate that you take care and consider suggestions. I have tried mostly all professional plugins, but I believe your plugin is on a good way to become the no. 1 plugin for related posts.
Another suggestion is a sidebar widget, but there would be many further ideas and I believe you have already a long list of features.
However, I can not stress how important it is to include the functions as described in my first suggestion. The most important is to have an easy “related posts” query which can be configured, and because mostly anyone uses category and tags in WP to relate posts, such a function would be basic.
Just a last tipp: Currently the best related post plugin from my opinion is “Super Post”, it has simple but extensive configurations to create querys and may help to get some ideas!