I've never used one but have seen videos and photos of them and can't get why they wouldn't stick with the design. It seems simple and far better then having an electric start push mower.
Can anyone who used one of those or knows about them explain why they never really caught on? They seem great.
[youtube=425,350]http://www.youtube.com/watch?v=KsxwHnc7GFs&feature=related[/youtube]