The final installment of Concurring Opinions' interview with the creators of Battlestar Galactica is now available here. This part focuses on the Cylons.
Personally, I find the Cylons less interesting than the rest of the BSG setting. The issues they raise (e.g. - the moral status of intelligent artificial life) have been done to death in earlier science fiction. Moreover, it's very difficult to take the moral claims of the Cylons seriously in light of the fact that they have just exterminated tens of billions of innocent people and nearly wiped out the human race. Some interesting issues are raised by the Cylons' monotheistic religion (contrasted with the polytheistic paganism of the series' humans). BSG co-creator Ronald D. Moore deserves credit for being one of the few producers of science fiction TV series willing to take religion seriously (which he also did in his earlier work on Star Trek: Deep Space Nine - the best of the Star Trek TV series in my distinctly minority view).
Most people raised in the Christian, Muslim, or Jewish traditions unquestioningly assume that monotheism is clearly superior to polytheism. By making the "bad guys" dogmatic monotheists and the "good guy" humans a combination of polytheists and atheists, BSG questions that assumption.