No experience to report, just interested. I wonder if kids learn balancing earlier. My daughter is almost four and it has been only in the last few months that she has got the pedal motion on a trike, till then she was pushing with her feet (quiet fast I must say...) and is now ready to move to a bike.. with training wheels.
I wonder if these kiwibikes don't do a better training job. I agree with the info on the site, till three or three and a half, pedals are on the way, they just don't get the motion, but can push pretty hard on their feet!