CSS templates:

Pro: CSS templates save loads of time once you understand them. For example, setting up the little 3-page website took only a short amount of time using a template. Also, changes can be made easily to effect an entire site's pages.

Con: The only con I can think of is that that is a learning curve with this and I am just starting to learn, so it is frustrating at times.

CSS Positioning:

Pro: A very handy way to position elements visually on the page (in design view).

Con: The absolute/relative seems conterintuitive at first.