For a long time, I hypothesized the Cylon "plan" wasn't to eliminate humanity, but rather to replace it - and become God's favorite.
In order to accomplish this goal, the Cylons reasoned they needed "souls", which their experiments showed humans possessed and Cylons lacked. Hence, the attempts to mate with humans and the importance of Hera.
Just a hypothesis.
Now the plan is unravelling.
Duis digrissim ipsum in rana unicornis!