I'm gonna go with Robo. I haven't played Chrono Trigger past the first forest (Got lost, didn't know what to do/where to go), so I stopped there and haven't picked it up since. But, from what I've seen of CT, and my mastery of CC, I preferred Robo over Ayla, who seems to be a lot like Leah from CC. (And I'm fairly sure that Gaea's Navel is an island that was transported to the CC world from CT's distant past.)