Just FYI, you're replying to a three year old post. One of the really annoying features of the new Forum format is the faintness of the date/time stamp on posts (left side, between the post text and the "like" button).
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .