I've also just been watching BSG season 3, and it struck me...
A character, thought at the start to be one of the bad guys, ends up in jail, starts jotting down his thoughts, and starts a religious movement.
On the one hand, Citizen G'Kar. On the other, Gaius Baltar, former president of the 12 Colonies.
When I look from one character to the next, and see the base similarities in those parts of their arcs, I come to realise that I am highly dubious at the end of the day that Baltar will be anywhere near as interesting a character as G'Kar.
And that's fine, different characters, different stories. But I think Baltar is the weaker for it.