Did the bipedal walking people try optimizing for energy instead? If so, and the models were still choppy, maybe that's actually better.

I guess I just find the goal of imitating human intelligence including all its mistakes to be a silly goal. The only time you want that instead of an actual human is if you're trying to deceive people into thinking your AI is a human. Otherwise, you just want the correct answer (or, if you're afraid, you want a strictly sub-human intelligence).