The flashbacks better have some relevance because I am tired of the writers always focusing on the past. I would much rather they carried on moving forwards. Caprica is gone. Get over it. Lets focus on what's left.
I think the flashbacks are effective because it ties into Baltar's speech to Lee about a new life and building that life, etc. In a way, the ragtag fleet has never really let go of Colonial society, and Lee's new Quorum and government is a start to that.
Moreover, at the end, we see where they began, again. I feel it a nice juxtaposition.