I have an older Mantis and it works fairly well in some areas but I don't think it lives up to it's advertising. It's small and light weight which is fine for breaking up chunky soil tilled by larger machines but it won't chew through grass as advertised, unless you have all day to do a 10' square area. The biggest problem I found is that in hard soil it bounces which can be very dangerous. I don't know anything about the new one though.