Sturdy, except for the corner chairs which come loose, but that is when I sit on them, and those are easily fixable and are nice to have.  For the price this is an affordable and pretty decently made sand box.  My kids love it and the overall size is pretty good 3 kids could easily play in this.  We have 25 50 lb bags of sand in it and that seems to be enough... getting the sand to your house and into the box is the hardest part of the assembly.

Pros: good value, easy to assemble
Cons: sit comes loose