I'm gonna raise my rating for this second set of five episodes to the maximum. The reason is that this is what the series is all about, great character development. Motivations are illustrated, not just for the main characters Renton and Eureka, but for many side characters as well. I think the best way to describe this is to tell something about the episodes without revealing too much.
Episode Six: Renton is hounded by Eureka's adopted children, whose main goal seems to be to drive him off the ship. A naive, but selfless action taken on his part helps him form a bond. It basically lands him in the brig, but at least he's coming to some understanding.
Episode Seven: Now that he's bonded with the children, what about the other crew. They send him on a fake mission to test his mettle, or perhaps just make a fool of him. In getting their jollies, they come to know more about his character, and he becomes closer to being a real member of Gekko State.
Episode Eight: Can a friendly old woman really be a terrorist? Apparently so, and will the Gekko State profit off of turning her into the government? Renton sees some of the more disturbing sides to the business in this episode.
Episode Nine: Eureka revisits an undesirable past, and it comes back to haunt her went confronted with a place she's known before. For some reason the people of a destroyed town know her well, and don't seem very friendly about it.
Episode 10: Feelings would be an appropriate title for this episode. It explores, Renton's, Holland's, Eureka's, and other characters motivations to some degree. On the enemy side, a strange girl is introduced. Could she have some connection to Eureka?
Now that I've summarized this, realize that we've not progressed very far at all when it comes to the real plot of the series. Fans of other series might call these filler episodes, but to call them fillers in Eureka 7, you may as well designate 90 percent of the series as filler. These are episodes that develop the story and the characters. Like a good book you need to know what motivates people to become the way they end up. People are not just Superman like heroes that stand for, truth, justice, and... well you know the rest. They don't just run off to battle without reasons, and those in themselves can be very complex.
The production values of this second group have not fallen off one lick from the first five episodes. As mentioned in my review of the first five, the path does not really become clear until a major element is revealed in episode 29, which is actually the third season of this series. This series is one to just sit back and enjoy the development and gain an understanding of the motivation that drives the characters. There will be action to come, but Evangelion, this is not, so don't look for the mecha battle of the week here.
My personal recommendation here is that after buying the first box set, wait and watch this on the CN till more episodes are played. If you still like the series after you're halfway through, then start to fill in the spaces the first box has allotted for DVDs. I'm guessing that since this is a 50-episode series, at some point around episode 25 or 30, there will be another box set released with spaces for the final DVDs.