Pros:
Sarah is just so smart. Sometimes you can forget how much random stuff they had to learn on the way. You could ask for an idea on readings/who to go to, and she'll drop a really random study in a completely different field, and say there's a intersection there, find it and relate it back. You do this, you hand in your paper. Boom: First
Cons:
Nothing about Sarah, but it does mean that the bar is raised and many of your other lecturers will fail to meet this standard. That may become depressing. No worries, just choose all of Sarah's modules.