I don't know what was different about this time, but Kate finally 'got' it this time. The system isn't perfect but at home we are accident free. Nighttimes are about 50-50. Outings are not so easy. The 'big' potty scares her and though she will sit on it, she doesn't ever go potty.
I'm happy for us. It's not exactly easier than changing diapers, but it is best for her in the long run. To be honest, it makes me think about starting Ben. :)