Incoming Search Terms Plugin - For / Against

I just see many of my competitors use this plugin. What you suggest me, to install this plugin or not?
I saw many for / against about this plugin. Some reviews said that after installation (24-48 hours) their websites dissapeared from Google, some says that website have x5 more traffic after install.
Do you have this plugin installed? You suggest me to install? What are the best and safe settings?

It is not possible for this kind of plugin will make your website disappear, LOL

By the way, I use Statpress for all my websites. This plugin also has incoming search terms features. I have no problems at all, all my website ranking well on search engine.

How does the plugin know the search terms from Google if they remove those from the referring URL?

I use SEO Search Terms Tagging for mine. I have no idea how the plugin tracks the search terms but it does track them.