Our metaphysics course stood squarely in the Aristotelian tradition of examining the nature of reality, or "being qua being". An alternative approach was mentioned, however. As I understand it, the Kantian tradition instead limits itself to examining mental constructs, or the conceptual schema which underlies our understanding of the world.
Based (perhaps loosely) upon those two opposing traditions, I find myself thinking that there are two 'ideal' ways of approaching metaphysics. Both should be scientifically informed, but in different ways: the one by physics, the other, psychology.
The 'folk metaphysician' would make no claims about the nature of reality. Instead, he would help us to understand ourselves. Furthermore, he would play a crucial role in the development of Artificial Intelligence. For without some coherent conceptual schema for analysing the flood of data provided by its input sensors, an AI would have little hope of understanding the world around him. In this way, metaphysics - seemingly one of the most abstract branches of philosophy - would in fact serve an important practical purpose.
The problem with the metaphysics we studied, is that it mixed these two ideals. It was based on the common-sense, rather than scientific, structures. Yet it still made claims to objectivity, to representing the fundamental nature of reality. I found that mix to be rather implausible. It would be better, I believe, to pick one of the two 'ideals' outlined above, and stick to that. You can have reality, or common sense, but not both.