As others have mentioned, however I would also stress the legal aspect of it. We had a briefing with the company lawyer that covered many possible scenarios and what we can and can't do which was very useful. Why this isn't taught to FOs I don't know however. Apart from that for me it seemed a general test of knowledge probing parts of the ops manuals that you rarely reach for rather than a course teaching you, although I suspect like most other people it highlighted the odd area that you had lack of knowledge or a misunderstanding.
I was amused by a comment at my final management meeting before flying the line. The gentleman in question (and he is a true gentleman) said 'You'll go from trying to get the slickest approaches possible thinking you have made the captain happy to being the most happy when the FO makes an average approach to average landing all comfortably within stability criteria.' How true.