I bought two pairs for my boys, a four and a two years old. For my two y/o, everything went perfectly. For my four y/o, it's either a defective product or the fact that it was stretched to the longest size, but the right skate detached twice.
We still had an awesome moment skating for the first time with our boys. Those skates will definitely work from 18months old to 4 y/o. They feel sturdy, should last for 2 or 3 kids. If the straps fail, they can easily be replaced by large velcros or tape.
We will be using them on the Rideau Canal in couple weeks. They are very easy to deal with since you only strap them under the child's boots.