The two-episode format mainly suits a series that's going to put a heavy emphasis on the monsters of the week. (It means you only have to make at most 26 MotW suits.) So in Kuuga and W, it was tops. I'm kind of glad someone's not using it out of reflex, though.
OOO didn't really look like it was going to go in that direction. The show's just not about the Yummys or the people who turn into them. Kobayashi's interest clearly lies in writing about her principal characters, their relationships, and the broader situation.