Just answered my own question! Apparently I asked this question previously and re-read the response. Haven't been paying attention as close to AS these past couple months! Thanks anyway!
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 .