The Season 1 set that I have of BSG has no special features other than a series of (very interesting) deleted scenes. Season 2, however, has deleted scenes and commentaries on most of the episodes by Ronald D. Moore. I started listening to the commentary tracks and was blown away by how descriptive Moore is. In a way, his commentaries offer an interesting corollary drama to the main drama of the series itself, which is the struggle to get the show on the air and keep it consistently good. He talks about many different elements of the production, but from it you also get a sense of how the series is being planned out. It's all very interesting.
I am considering getting rid of my miniseries and UK sets in favor of the standard release, which also contains commentaries on most of the episodes. I am particularly interested in hearing the one for my favorite episode of the first season, "Act of Contrition."
The episode "Final Cut," guest stars Lucy Lawless as a reporter making a documentary about life on the Galactica. There is a moment where she shoots Edward James Olmos and Michael Hogan having a private conversation. Moore says that he doesn't feel that he ever succeeded in communicating how much of the conversation is being picked up on camera and how much isn't. I was surprised when I heard that he even attempted to try; I found the ambiguity very effective in context of the episode, because as a viewer I was unsure... so I was experiencing something very similar to what the characters were. See, the show is so good even the screw ups are effective.