These work well - until they snap!  Within a month after I put them on my Kindergartner's shoes, 2 laces broke and now I have no more extra to change to.  It seems like the laces twists around when my daughter sits on the floor her legs crossed and that's how the laces get damaged and eventually they brake.  I wonder if they can re-design kids laces wider or different shape so they won't get twisted much....
To be fair, I have been using Hickies tieless laces for my shoes for about 2 years and none of them broke!  I would give 5 starts to my Hickies but I can't give 5 starts for kids one.