At the same time, I can find comments problematic. They often run off on rabbit trails or become a heated online "shouting match" rather than profitable discussion. I have especially seen difficulties when extended (or more complex) thoughts are written in a series of posts. People begin attacking the main point or thesis without even reading all of the support or reasons a blogger makes. It reminds me of reading the conclusion of a research paper and judging the work without even bothering to see how the writer tried to establish his or her case.
As a result, when I post a series on my blog, I have decided to only allow comments on the last post. I realize this decision may not be the perfect answer, but it seems to be the best. Of course, I reserve the right to change my policy at any time (what blogger wouldn't?). Nevertheless, I want to give this idea a try and see how it works.