The Mixx Tour didn't work for me so I moved to Digg. I liked the layout of Digg better and the flexibility in selecting only those categories that I am interested in and hiding the rest. I also liked that I can share what I am reading with my friends on Facebook.
I liked the way NewsVine organized its tour with the comment "You don't have time for a long demo. Here are 4 reasons to make NewsVine your news site." A very clever and direct way to market your site for people who are strapped for time, which is everyone! I found it interesting that the Reddit introduction was last updated 3 months ago which seems like a long time. I much prefer to visit a site that is updated more frequently!
I went to BBC and recommended an article to Digg but it had already been submitted by another user so I put my vote in!