The Sandman is a story that is very interesting and can work really well on paper. However, the plot is executed very poorly, and falls in line with a lot of other more middling Who stories. It's not particularly interesting or memorable, and is probably one of the skippable story out of all of 6's Main Range entries. Unless you're planning a full run-through of 6's (or Evelyn's) run, I would just let this one pass you by.