ANyone use this tool much?

Basically it sandboxes problematic users, the users post away thinking their posts are visible to all, when in fact the posts in invisible to everyone else, this is a good way to isolate trolls and other low quality users.

I'm not sure whether to implement this or not, I'm thinking more along the lines of a timeout written warning where the troll has his/her posting rights removed for a certain period.

WHat are your experiences with hellbans?