I hope this anime goes to 26 episodes. I can't see them cramming everything into 13 episodes. Especially if the plan on introducing Stella and Asmaria.
Great first episode though. I liked how they had the GeoBreeders BG music playing in the background.
But like everyone said, I'll stick with it before making a final judgement. If I had put Maburaho off after the first episode (Like I did with Gilgamesh) I would've missed out.