That was a neat little episode. I enjoyed the inclusion of new faces (and while I'm sure she won't, I'd like to see Drummond again) and the subplot of Watson's apartment. The bit about her being Sherlock's friend felt a little forced for her character, but it fit and it's paving the way for the direction the series will be going with their relationship. It was engaging and contained and finally felt more about the main characters than the case of the week, which I think has been much of my problem with the show up until now.
And gifts with bows! I really want to know what happened to her toothbrush.