Help! In the Gospel of Luke, what are the most pressing exegetical conundrums?

I am currently reviewing a commentary on Luke and because of its incredible length, I am at a bit of a loss as to where the focus of the review should lie. I am, of course, going to discuss introductory matters (purpose, authorship, context, genre, etc..), but what passages and verses are folks most curious about? What are the most pressing exegetical conundrums?